I was thinking of getting tent/ folded business cards that have a tear away contact form. I like the idea of leaving with a lead in my hand and can follow up with that person with out waiting for first contact from them. It keeps me fresh in their "mind" and builds a nice referral/ network list for me!
Something else I was looking at was the great cards that MOO (moo.com)has. I really like the mini cards. Not to bad on price.
I'm loving all the ideas for the backs of the cards, especially the one's that define the field or specifically geared to the business.
For those that printed cards and want to use the great ideas everyone came up with; use the old cards as magnets or stickers.

No harm, no foul!