My buddies at Card Cues just came out with a Do-it-yourself imprintable version of their POP business card holder. If your marketing strategy includes placing a number of your cards at various venues where they can be picked up. Card Cues has a great solution and the addition of this DIY customizable version which allows you to create and print your own design is extra cool. Take a look at the detail on their website.
DIY Custom Imprinted Card Card Holders