Send a picture PostCard to your frends. Cards are stored in a flat file back end. Old cards are automatically expired. Soon to come, hopefully, is a commercial version with features like dbm back end and file uploading.
A really great thing about BIS Postcard is it's Simplicity. Users don't have to jump through radio buttons and check boxes and complicated forms just to send a card. All they need to do is click on an image, then fill in To, From, and the message!
