While old-fashioned business cards have their charm, it's a little surprising that a digital service like Contxts, an SMS-enabled way to share contact info, hasn't come along sooner. After entering info online, users can send their "text card" to mobile phones (or someone can request it) by texting the preset Contxt number. The new contact then receives the info and they're entered into a virtual rolodex accessible through Contxt. Tapping the power of social networking, all the other details, like Facebook, Flickr, Twitter, etc., that they've provided on their profile also become available to connected users.
Contxt is still currently in beta, but sign-up on their site to start text-networking.
Thanks to @schatz for the tip!