On my PC's I use Crap Cleaner (http://www.ccleaner.com/)
Cleans the following:
Temporary files, URL history, cookies, Autocomplete form history, index.dat.
Temporary files, URL history, cookies, download history.
Recycle Bin, Recent Documents, Temporary files and Log files.
Advanced features to remove unused and old entries, including File Extensions, ActiveX Controls, ClassIDs, ProgIDs, Uninstallers, Shared DLLs, Fonts, Help Files, Application Paths, Icons, Invalid Shortcuts and more... also comes with a comprehensive backup feature.
Removes temp files and recent file lists (MRUs) from many apps including Opera, Media Player, eMule, Kazaa, Google Toolbar, Netscape, MS Office, Nero, Adobe Acrobat, WinRAR, WinAce, WinZip.
It does a fantastic job, cleaning about 100 mb plus each time I use it.