I'm not sold on the back of the card. A lot of people stick my card on their computer or in a business card slot where you can't see the back of the card. My business clients know me as the computer guy, not the guy that can do this, or this, or that, and this too. And if it's not on the list, do you think they'll call you? Maybe, but maybe not.
My point is that if you just have good relationships with business clients and potential clients, you can drop the back of the card (which looks a little cluttered anyway) and still get their business.