I tend to research stuff to death. Example: I'm looking for a small flashlight that works well as a flood. Lo and behold, there's a flashlight forum with members that are as enthusiastic about flashlights as guys are about modding their trucks. I mean there are flashlights that are hundreds and hundreds of dollars. I'd never spend that, but some people would never spend $10k on a turbo setup, so who am I to judge?

Anyway, thought it'd be interesting to see what other "odd" forums you've run across (or can find). Seems like there's one for everything.