I'm about to go way against the new trend here, especially considering marketing guy, Guy Kawasaki, just came out with a new card (BTW: I'm not calling it a business card, because IHMO it isn't one, yet) that I don't think will be very effective as a business card.
You'll see lots of other business teachers on the net ooh'ing and ahh'ing about these "trendy" new cards, but IMHO they are going to be a passing fad.
All they really do, other than stoking the ego of their owner, is give a great WOW factor during the initial introduction.
Here is what I mean: The front is black with just his name in big bold white letters (like I said: an Ego card).
While this will certainly get some attention (and it seems most of the people who comment on his site like it) it really doesn't do anything as far as letting people know what he can offer them.
Moving on to the back of the card we see it is also all black (consistent at least) with a few contact points, three website addresses, an email address and a cell phone address.
So the card does indeed have some contact information like a business card.
This is truly an attention getting card! I'm sure this type of design will be good at generating buzz during the initial meetings simply because they are so out of the ordinary, but it really doesn't do what a business card is good at doing.
Giving the receiver some information about how you and your business can help them.
It would only take a couple of simple tweaks to make this card into a powerfully effective business card.