I just received my newest set of business cards from a company called myminicards.com. I am really happy with the service that the company provided. I uploaded my files via ftp on Thursday morning and then received my cards on Saturday! Not too shabby.
The print quality on the cards is really good. The thing that sold me was the fact that I could submit up to 25 photos for the back of the cards as well as 1 file for the front. Most companies will only print photos on the back of the card and then print text on the front.
My overall experience with myminicards.com has been great so far. The cards ship for free and come with a cool little card holder/dispencer. I might just go ahead and use them again for my next batch.