it's own website: Toybuilderlabs.com. I can already vouch for the exceptional quality of both his PLA, which was an incredibly painless first time experience with the stuff, and ABS. In fact my next round of Chessbots will all be Toybuilder Labs ABS. His prices are only slightly higher than the cheap stuff, but the quality is as good as the expensive stuff.
So if you're in need of Filament I recommend you send some business Joseph's way.