Harold's Home

Found this great review of completely useless software on PerversionTracker.com: PT Bruiser.
It's a browser with a twist, it will only allow you to visit perversiontracker.com, although there is a hidden feature that enables you to visit other websites. I spent a good half an hour before I was able to visit my own homepage screenshot.

If you're running MacOSX give it a whirl, and have fun.
Hint: click the "sponsored by l33t.com" ad and be aware that you can only get to other sites by clicking on links. Try to find one to Google and you're home free.