Seeing as there are no worthwhile benefits from belonging to a graphics team aside from potential reputation on a website, I'd suggest not worrying about it too much. You're either good with graphics or you aren't.
Well I know NL a little, and they wont aproach anybody unless they have "street rep"...people that are already knowen are only really going to get chosen =\ as Comatosis said, not much point really =\
err, i didnt have any 'street rep' before i got into NL. only started gettin rep after i got in NL, if thats all that matters in graphics crews in ur eyes. bit of an arrogant thing to say. totaly agree with u ther Statusquo, thats wat a graphics crew is, a group of friends who like to do graphics which u can get some gd solid advice from, imo iv improved ten fold since i got into NL.
Crews are a complete waste of time...all they do is make "sigs" and try to feel big. They serve no purpose. Something that would be worthwhile to join would be something like a team which make websites and sell them for money.
Learning new photoshop techniques from a graphics crew is no different from learning them from internet tutorials or books, so it still dwindles down to this: a graphic crew's sole purpose is to establish and maintain a meaningless net reputation.