James Michael over at Global Knowledge has put together a great list of online (and offline) security tools everyone should know about. I use many of these myself and even found a couple of new ones in the mix I haven’t checked out yet.
You can find the PDF here:http://www.globalknowledge.com/training/whitepaperdetail.asp?pageid=502&wpid=1297&country=United+States
It’s a quick read with great info.