Tradecards, considered to be the predecessor to business cards, were first used in England in the 17th century. They were used for advertising and as maps since there was no formal street numbering in place. From these humble roots the tradecard has over the last four centuries evolved into the modern business card. The business card will continue to morph in the 21st century and you might consider these options to stand out in the crowd.
Perhaps the most unique business card ever is from Meat Cards. If you want your business card to stand out than consider a card made out of 100% beef jerky. They take the beef jerky and sear your contact information into it with a laser. These cards are still in prototyping but should be unleashed upon the world in the near future. You are guaranteed that folks will remember you - unless of course they are stranded in an elevator and have to resort to eating your business card. Of course, in that case they most certainly will remember you - they just won't have your business card so they won't know how to contact you.
Recycled cards are a great way to lessen your carbon footprint while creating a unique image for your business. There are a lot of options out there from recycled paper, to soy-based ink, to reused paper and materials. You can contact Sustainable Group (paper from 100% recycled fibers), around $115 USD for 500 cards or En Masse Media (100% post consumer recycled paper), around $150 USD for 1,000 cards. These cards won't be as tasty as Meat Cards, but considering how often business cards are tossed aside you can feel better about this choice.
You can also go a step further and eliminate the need for a tangible business card with DubMeNow. The idea behind the Vienna, Virginia based DubMeNow is that anyone with a smart phone can use the DUB application and instantly exchange (via text or email) all their contact information (email, phone, company, address, title, etc.) to another smart phone. The contact data loads directly to the user's mobile address book, the web and updates automatically whenever a contact changes their information. Dub eliminates the need to swap, save, enter or update any more business card data. DUB will also make it easy to invite contacts to connect via social networking sites, 'tag' or note information about the contact and see when and where you met.