I love my Moo cards. I don't know if they're really distinctive as such, when every nerd/hipster here in SF that I know has them, but I love the fact that I can use my own flickr photos on them, and they've got a nice feel and much nicer typography than, say, versaprint.

As far as the size goes: nobody keeps business cards these days. Either they enter you into their phone/computer contact DB within a few hours of getting the card, or they find it in their wallet/purse months later and throw it away after failing to remember who you were. So I don't worry about that. :)