I'm lazy & sometimes I forget to clean something. So I use CCleaner ("Crap
Cleaner"), a free software tool that blows away temp files, cookies, last
viewed files, history, and more.
http://www.ccleaner.com/.Run it after any use to
keep your computer nice and tidy (& pry safe) without having to remember
what to delete.
Also - as I mentioned to somebody the other
night, make sure you've also run some spyware detection to make sure he
doesn't have a sniffer installed that collects passwords, chat sessions,
keystrokes, etc. A good one (not free though) is Spy Sweeper by Webroot,
http://www.webroot.com/En_US/index.html.(If
he's really stealthy though, he could come in and work around Spy Sweeper
by telling it to always ignore certain programs, so, your mileage may
vary.)
rd