sapphire.... you have to have the mark of the mod... it's a strangely shaped birthmark on your right shoulder that looks similar to a sphere-shaped slug..
basically, all of the mods (except for shane and Matt K) started off as normal members but as they continued browsing the site, Jeff noticed "mod-qualities" in their posts etc... what are mod qualities exactly? I don't know... maybe somebody else can answer that
I may be wrong but in my opinion, this is probably how mods are chosen...
Oh and Trev, if my several messages of block capital letters congratulating you weren't enough, congrats again!!