I've been using one called the ArcDev duofilter. Its a rad dual filter (that u can chain) with distortion. The distrotion is absolutely crap but the filter is really fun because it has a crossfader between the two filters. And I think its free. I can't remember where I got it either.

Ah here we go http://st2n.com/daw/cgi/database/apd...en&num=298