I would prefer print on demand, since fulfillment is challenging, and even more so when you don't have a permanent home. I've used CafePress and Lulu in the past, but have not been happy with them for different reasons. I'm not looking to make a lot of money off them, but definitely want the ability to customize them with my url so they have some value in terms of marketing. And, if I find a place that does a good job, I will probably order a dozen or so to have on hand when I want to give someone something more than a business card.