The latest update to Picased (v0.4) uses thumbnails instead of the larger image. The RSS feed is located at the bottom of every album.

check out:
Picasaed, the WordPress Picasa Widget has Been Updated

The download link here does point to the newest version though.

< ?php
//options
$feed = 'your album feed'; // enter your album feed here
$link = true; // should images link to album
$number = 4; //number of images to display

$feed_content = file_get_contents($feed);
if($link){
preg_match("/href=[\"']([^\"']+)/si",$feed_content,$album_pre);
preg_match("/[A-Za-z0-9\/:.]*\/+/",$album_pre[1],$album);
$open_link = '<a href="'.$album[0].'" rel="nofollow">‘;
$close_link = ‘</a>’;
}
preg_match_all(”/media:content url=[\"']([^\"']+)/si”,$feed_content,$photos,PREG_SET_ORDER);
$picased_now = ‘<ul>’.”\n\r”;
for($i=0;$i< $number;++$i){
$photo_rss = str_replace("media:content url='",'',$photos[$i][0]);
$photo_explode = explode('/',$photo_rss);
$num_explode = count($photo_explode);
$photo_explode[$num_explode] = $photo_explode[$num_explode-1];
$photo_explode[$num_explode-1] = 's288';
$photo_url = implode('/',$photo_explode);
$picased .= "\t".'<li>‘.$open_link.’‘.$close_link.’</li>’.”\n\r”;
}
$picased .= ‘</ul>’.”\n\r”;
echo $picased_now;
?>

if you want pure html, then you’ll need to do the work I’m afraid to say.