I'm a newbie to Lego in most respects. I've been playing with them since I was of the age in which one is relegated to playing with Duplo blocks, but I wasn't able to collect Lego sets until recently. I only had one little bucket of them, plus the random pieces I unearthed in our backyard. Because for some reason our yard was like this Lego burial ground, you couldn't dig anywhere around the porch without finding some.
I have two main interests in Legos: dinosaurs and Star Wars. I'm on the fence about Halo, since I love the armor designs and the fanfiction but haven't played the games. I don't craft my own custom Lego pieces, but I am a 3D modeler and am starting to see ways in which the realms of 3D modeling and custom pieces seem to intersect, which sounds interesting. I'm happy to have found BrickForge and learned that you can actually buy customs instead of making them from scratch.
Non-Lego interests of mine include programming web sites (which is also what I do for work), creating custom mods for games like The Sims 2 or Creatures, and writing science fiction. I'd add something non-creative to the list, but... well, I can't really think of anything. :P