...Try http://www.informatik.uni-frankfurt.de/~polzer/rbiclan/location
The page is SUPPOSED to prevent going to somewhere else by changing
the URL back in onUnload (even that is already a reason to disable
JavaScript).
The interesting part is: depending on browser, you see different bugs...
Mozilla, Netscape 7 or Firefox: almost works correctly. Except for two
small bugs: View source shows the source of Google or where you TRIED
to go to, while you SEE the unload-trap page. The other bug: when you
close the browser window, onUnload is executed TWICE (you see two
alert boxes, with the number increasing) and the new page is loaded,
but not displayed. But the view-source bug somehow looks suspicious.
Do other parts of Mozilla think it was another website too?