Here's now to get the most recent public Buzz entries for a given user. Google offers the list at http://www.googleapis.com/buzz/v1/activities/USERNAME/@public, where of course the USERNAME must be changed into something meaningful. The default format is XML (yech), but adding alt=json fixes that. The default number of returned entries is 20, but that can be limited by e.g. max-results=5. Here's an example of my latest one Buzz (the listing gets kind of long when you fetch more, and I replaced some too long URL's with ... and inserted arbitrary newlines):

  bash$ curl 'www.googleapis.com/buzz/v1/activities/kkubat/@public?alt=json&max-results=1'

  {"data":{"kind":"buzz#activityFeed","links":{"next":[{"href":
  "https://www.googleapis.com/buzz/v1/activities/108588487512525984185/@public?..."}],
  "self":[{"href":"https://www.googleapis.com/buzz/v1/activities/108588487512525984185/@public?alt\u003djson",
  "type":"application/json"}],"hub":[{"href":"http://pubsubhubbub.appspot.com/"}]},
  "title":"Google Buzz Public Feed","updated":"2010-06-08T10:50:01.127Z",
  "id":"tag:google.com,2010:buzz-feed:public:posted:108588487512525984185","items":[{"kind":
  "buzz#activity","title":"Sushi Saturday - great fun for all, pics at
  http://www.kubat.nl/pages/blogaria/185#185. Plus,
  Ste...","published":"2010-06-07T09:35:17.000Z","updated":
  "2010-06-07T09:35:17.782Z","id":"tag:google.com,2010:buzz:z12lhzwoyvz5z1qfl23rx1vztyrdzdyue",
  "links":{"liked":[{"href":
  "https://www.googleapis.com/buzz/v1/activities/108588487512525984185/@self/tag:...",
  "type":"application/json","count":0}],"alternate":[{"href":
  "http://www.google.com/buzz/108588487512525984185/L247NmucVAq",
  "type":"text/html"}],"replies":[{"href":
  "https://www.googleapis.com/buzz/v1/activities/108588487512525984185/@self/tag:...",
  "type":"application/json","count":0,"updated":"2010-06-07T09:35:17.782Z"}],"self":[{"href":
  "https://www.googleapis.com/buzz/v1/activities/108588487512525984185/@self/tag:..."}
  ]},"actor":{"id":"108588487512525984185","name":"Karel
  Kubat",
  "profileUrl":"http://www.google.com/profiles/kkubat","thumbnailUrl":
  "http://www.google.com/s2/photos/public/AIbEiAIAAABDCLmj9e-4_JuYdyILdmNhcmRfcGhv..."},
  "verbs":["post"],"object":{"type":"note","content":"Sushi
  Saturday - great fun for all, pics at \u003ca
  href\u003d\"http://www.kubat.nl/pages/blogaria/185#185\"
  \u003ehttp://www.kubat.nl/pages/blogaria/185#185\u003c/a\u003e.
  Plus, Steve Martin is a champ at sending personal letters - ghe ghe
  - at \u003ca
  href\u003d\"http://www.kubat.nl/pages/blogaria/186#186\"
  \u003ehttp://www.kubat.nl/pages/blogaria/186#186\u003c/a\u003e","links":{"alternate":
  [{"href":"http://www.google.com/buzz/108588487512525984185/L247NmucVAq","type":"text/html"}]},
  "attachments":[{"type":"photo","links":{"preview":[{"href":
  "http://images0-focus-opensocial.googleusercontent.com/gadgets/proxy?container..",
  "type":"image/jpeg"}],"enclosure":[{"href":"http://www.kubat.nl/bld/SushiSaturday/imag0057.jpg",
  "type":"image/jpeg"}]}}]},"source":{"title":"Buzz"},"visibility":{"entries":[{"id":
  "tag:google.com,2010:buzz-group:@me:@public","title":"Public"}]}}]}}

curl 'www.googleapis.com/buzz/v1/activities/kkubat/@public?alt=json&max-results=1&prettyprint=true'

{
 "data": {
  "kind": "buzz#activityFeed",
  "links": {
   "next": [
    {
     "href": "https://www.googleapis.com/buzz/v1/activities/108588487512...",
    }
   ],
   "self": [
    {
     "href": "https://www.googleapis.com/buzz/v1/activities/108588487512...",
     "type": "application/json"
    }
   ],
   "hub": [
    {
     "href": "http://pubsubhubbub.appspot.com/"
    }
   ]
  },
  "title": "Google Buzz Public Feed",
  "updated": "2010-06-08T11:09:13.237Z",
  "id": "tag:google.com,2010:buzz-feed:public:posted:108588487512525984...",
  "items": [
   {
    "kind": "buzz#activity",
    "title": "Sushi Saturday - great fun for all, pics at http://www.ku...",
    "published": "2010-06-07T09:35:17.000Z",
    "updated": "2010-06-07T09:35:17.782Z",
    "id": "tag:google.com,2010:buzz:z12lhzwoyvz5z1qfl23rx1vztyrdzdyue",
    "links": {
     "liked": [
      {
       "href": "https://www.googleapis.com/buzz/v1/activities/108588487...",
       "type": "application/json",
       "count": 0
      }
     ],
     "alternate": [
      {
       "href": "http://www.google.com/buzz/108588487512525984185/L247Nm...",
       "type": "text/html"
      }
     ],
     "replies": [
      {
       "href": "https://www.googleapis.com/buzz/v1/activities/108588487...",
       "type": "application/json",
       "count": 0,
       "updated": "2010-06-07T09:35:17.782Z"
      }
     ],
     "self": [
      {
       "href": "https://www.googleapis.com/buzz/v1/activities/108588487...",
       "type": "application/json"
      }
     ]
    },
    "actor": {
     "id": "108588487512525984185",
     "name": "Karel Kubat",
     "profileUrl": "http://www.google.com/profiles/kkubat",
     "thumbnailUrl": "http://www.google.com/s2/photos/public/AIbEiAIAAA...",
    },
    "verbs": [
     "post"
    ],
    "object": {
     "type": "note",
     "content": "Sushi Saturday - great fun for all, pics at \u003ca hr...",
     "links": {
      "alternate": [
       {
        "href": "http://www.google.com/buzz/108588487512525984185/L247N...",
        "type": "text/html"
       }
      ]
     },
     "attachments": [
      {
       "type": "photo",
       "links": {
        "preview": [
         {
          "href": "http://images0-focus-opensocial.googleusercontent.co...",
          "type": "image/jpeg"
         }
        ],
        "enclosure": [
         {
          "href": "http://www.kubat.nl/bld/SushiSaturday/imag0057.jpg",
          "type": "image/jpeg"
         }
        ]
       }
      }
     ]
    },
    "source": {
     "title": "Buzz"
    },
    "visibility": {
     "entries": [
      {
       "id": "tag:google.com,2010:buzz-group:@me:@public",
       "title": "Public"
      }
     ]
    }
   }
  ]
 }
}

Right, this is better. The return value has the following structure:

• data is the main hash we're interetested in when we want to get at Buzzed items;
• items is the next one, which is an array;
• Each array element has an object;
• Each object has content which is the Buzzed text, and published is the publishing date;
• Also there is also a hash links with an array alternate, pointing to the buzz entries;
• There we are. In this example we won't fetch replies, or attachments, or whether someone liked the Buzz or not.

#!/usr/bin/perl

use strict;
use LWP::UserAgent;
use JSON;

my $public_url = 'http://www.googleapis.com/buzz/v1/activities/'.
  'kkubat/@public?alt=json&max-results=5&prettyprint=true';

# Get the latest 5 buzzes
my $ua = LWP::UserAgent->new();
my $res = $ua->get($public_url);
die("Failed to get buzz: ", $res->status_line(), "\n")
  unless ($res->is_success());

my $buzz;
eval { $buzz = from_json($res->content()); };
die("Bad JSON return: ", $res->content(), "\n") if ($@);

for my $item (@{ $buzz->{data}->{items} }) {
    print("Buzz: ", $item->{object}->{content}, "\n",
	  "Published on: ", $item->{published}, "\n");
    for my $alt (@{ $item->{object}->{links}->{alternate} }) {
	print("URL: ", $alt->{href}, "\n");
    }
    print("\n");
}

Buzz: You can read public Buzzes without any hassle - using Perl and
  JSON, what else - read more at
  <a href="http://www.kubat.nl/pages/blogaria/187#187"
     >http://www.kubat.nl/pages/blogaria/187#187</a>
Published on: 2010-06-08T11:58:10.000Z
URL: http://www.google.com/buzz/108588487512525984185/gkDfAzUGmbz

Buzz: Sushi Saturday - great fun for all, pics at
  <a href="http://www.kubat.nl/pages/blogaria/185#185"
     >http://www.kubat.nl/pages/blogaria/185#185</a>. Plus, Steve
  Martin is a champ at sending personal letters - ghe ghe - at
  <a href="http://www.kubat.nl/pages/blogaria/186#186"
     >http://www.kubat.nl/pages/blogaria/186#186</a>
Published on: 2010-06-07T09:35:17.000Z
URL: http://www.google.com/buzz/108588487512525984185/L247NmucVAq

Buzz: Quick note on suppressing auto-submit when someone hits the
  Enter key in an HTML form - at
  <a href="http://www.kubat.nl/pages/blogaria/184#184"
     >http://www.kubat.nl/pages/blogaria/184#184</a>
Published on: 2010-06-04T12:51:19.000Z
URL: http://www.google.com/buzz/108588487512525984185/eDkoRALSw3K

Buzz: Wormholes on the Dutch highways? I found evidence of that - at
  <a href="http://www.kubat.nl/pages/blogaria/183#183"
     >http://www.kubat.nl/pages/blogaria/183#183</a>
Published on: 2010-05-31T21:05:02.000Z
URL: http://www.google.com/buzz/108588487512525984185/8Npxwe7EXuf

Buzz: Dutch hosting provider Greenhost has stated not to log user
  traffic<br />More at
  <a href="http://www.kubat.nl/pages/blogaria/182#182"
     >http://www.kubat.nl/pages/blogaria/182#182</a>
Published on: 2010-05-25T06:54:03.000Z
URL: http://www.google.com/buzz/108588487512525984185/4ZvjNeWm6m1