When was the last time you received a piece of snail mail that wasn't a bill, invite or subscription? As we've become more and more dependent on our portables and inboxes, our mailboxes have become less and less personal. While there are some pretty sweet online postcard services, print cards can be treasured forever — or at least they can't be deleted. Next time you plan to send correspondence to a nerdy friend consider a more personalized pen pal message on one of these design-friendly and decidedly geeky cards.