Jacob Robbins, former head-of-software for Drop.io, has created a service called Burn Note that lets users send and receive secure messages by automatically deleting the message after it's been read. Each message is given a unique URL for distribution, and users can configure message settings to include password protection and a self-destruction timer configurable between 1 and 32,767 seconds.
Just how safe is this method of sending and receiving messages? Well, considering your notes don't exactly disappear completely — Burn Note actually encrypts and saves message metadata anonymously in a MySQL database for future survey research — we're leaving that for you to decide. The company's site includes a dedicated 'Technical Information' page detailing the entire process. But hey, this shouldn't stop you from trolling your friends with secret, self-destructing messages.