CCleaner (Crap Cleaner) is a freeware system optimization and privacy tool. It removes unused files from your system - allowing Windows to run faster and freeing up valuable hard disk space. It also cleans traces of your online activities such as your Internet history. But the best part is that it's fast (normally taking less that a second to run) and contains NO Spyware or Adware!

Warning: it will remove cookies, which is both a good thing and a bad thing. I have not seen (yet) a way to select cookies to NOT be removed, not saying there is not a way. Letting it remove your cookies will mean your login info on websites will be gone, you'll have to re-create those cookies and your login info,, but otherwise it looks great!

It's a "new" tool to me, but I just discovered it. Very small, looks very efficient, as much as I've seen.

Check it out here.