There are two feature rich Firefox addons I discovered recently.
First great program is Newsfox which converts Firefox into an RSS reader. It is a real light weight client which gives you all essential functionality.
The second program is Torrent Search Toolbar. This makes it possible to search 25+ torrent sites without actually opening them. It also reads RSS feeds from several sites and allows you to scroll through them. Cool!
Many torrents posted on these sites are illegal and one should be careful of what they download.