Simple roundup, all freeware:
- SlimBrowser: My choice for tabbed browsing on top of Internet Explorer (with built-in popup blocker). Some limitations but the developer releases new feature versions very rapidly and pays attention to the user community.
- GotDotNet Workspaces: SourceForge for the .NET folks
- HijackThis: Spyware finder
- Empty Temp Folders: does just what the name says, plus a little more.
- SharpReader: the current RSS Aggregator champ.
[mostly via Scobleizer]