I recently redesigned my business card, and I got to thinking of ways that I could make my card a resource in itself so that prosects would be reminded of my services.

I decided to put a 2008 calendar on the back so it could be used as a wallet reference. There are many things that I considered putting on the back. Amongst others, they were:
-Measurement conversion chart
-US timezone chart
-Notes section
-List of holidays

I made a huge list of potentials and then tried to narrow it down to what a prospective client would probably use the most.

What would you have put on the back, if anything?