Remember the days of real chain letters, real love letters you received in an actual mailbox and paper thank you cards? I love e-vites and social networking sites as much as the next person, but I mourn the loss of formal correspondence all too often.
Enter the eSnailer website, which allows you to type a letter to a friend or relative and will print, envelope, stamp, and send your letter via regular US postal mail free of charge.
From what I know, the person I sent a letter to hasn't received it yet, but that might just be because no one expects snail mail anymore. How is the site free you ask? It's supported by ads, so after you write your letter you will be asked to accept one of their free offers. Paper trails are so vintage geek.