You can also use an RSS feed to get the groups, and use filters on it;

http://brilliantdays.com/google-grou...has-rss-feeds/

http://www.readwriteweb.com/archives..._rss_feeds.php

this is probably the best option for somebody using a web based
interface. ( As opposed to a newsreader on your personal machine).

One reader which works well in Firefox is;

https://addons.mozilla.org/en-US/firefox/addon/629

A lot depends on the machine and software you use.

TL
MC