Card Observer

I know we've all seen the flickr sets and random posts that have been surfacing around the blogosphere on business card design lately, but in my opinion, the definitive source for business card design is Card Observer. It is constantly updated with new designs, so you'll see the newest trends and ideas as they're printed, and each card is featured along with both the designer and client's name so you can dig further into their work if you like. A brilliant idea and fantastic execution!