Ha, I like these little things, for anyone here who doesnt know these are called JavaScript injections, and a JavaScript injection can be used on any site, and all you do is input a code like this:
Code:
javascript:void alert('Coolprogram is the best');
into the adress bar, and then it will bring up w/e the command you inserted is, injections maybe used by some "hackers" like an SQL injection, but JavaScript injections are completely harmless, most of the time.
-CP