Vistaprint hooks a lot of people with "free" cards, but make you pay to upload images or even preview the card. But worse still, a lot of Vistaprint customers have found that VP will withdraw about $14.95/£9,95 from your bank account/credit card at least once a month after your purchase if you don't uncheck one of the dozens of checkboxes the site throws at you. Some people have been charged hundreds of pounds/dollars for their "free" cards.
If you complain about it they'll give you a phone number to call, in the US. And even then they're impossible to actually contact. The few people who do get through were promised a refund and received nothing. Many credit card companies and banks go "Uhm, durrr!" so you won't get your money back.
My suggestion is to pay a little more with a different printer and avoid getting scammed.
I have personal experiences with http://www.moo.com/ for example; their print quality is good, the paper is good, it comes in a little box to keep your cards in and shipping is fast.
Also, you can give each business card a different print on the backside if you like which artists can use as a little portable mini-portfolio.