I'm not at home now, but it seems like the cats or my hippie roommate have knocked the server offline.
Luckily, Kn1ves was nice enough to host a mirror found below (thanks!)
http://illusivedesigns.net/kn1ves/zi...h_Firefox.html
I just tested that one and it worked fine for me.
I'll get my server back up in an hour or so when I get home.
Edit: Now that I think of it, you may need to upgrade to Firefox 2.0. I don't believe the ability for Firefox to detect available searches was built into pre-Firefox 2.0 browsers.