Postcard.fm is a brilliantly simple idea: choose a photo, choose a song, and send them to a friend as a "postcard." The interface is totally free of frills and junk, making it incredibly easy to use. There's no way anybody could confuse this with the totally obnoxious animated postcards your mom or grandma email you. Plus, it's all hosted at Postcard.fm, so you won't be filling up your friend's inbox with files.

A few obvious uses for postcard.fm spring to mind: it's more thoughtful than a Facebook wall message for a friend's birthday, and it might even go over well as a surprise for a significant other. In a pinch, you can use it to share a song with a friend, if you don't have somewhere else to upload. There are some limitations, but they're not a big deal: it's mp3-only and just streaming, no downloads. The best part is that postcard.fm isn't at all ugly or tacky, so it's as considerate a way as we've seen to quickly show someone you're thinking of them via the Internet.