Thunderbird
Another application that I ran into over the week. Thunderbird 1.0 is an application from Mozilla that allows you to have a unified view of mail, blogs, newsgroups and RSS feeds. To me, it is extremely useful, because I keep shifting between Outlook Express, RSS Readers (like Firefox) and mail. After installing Thunderbird, I'm in love with it! I can now have a single view of RSS feeds, newsgroups, blogs and mail (I have not syncronized mail till now).
If you are interested, you can download it from here: Thunderbird