We recently developed a way to get rid of paper business cards and their shortcomings (e.g.: clutter). It's called Napkkin, and it lets you create a business card on your phone and swap it with people you meet by scanning a QR Code. You can get referred by your new contacts and get notified in real-time so you can track who's helping you with word-of-mouth referrals.
We've got mobile/desktop web apps and Android/iPhone native apps set up. We're looking for feedback, so let us know what you think!