Whether you're a Mission Impossible fan or simply someone who works in the service, y'know, someone who does "work", Privnote is a free utility that will let you write a message and send it through an e-mail as a weblink. Designed to be read once, and only once, when the sent link is clicked on and opened in as a web page, the message will cease to exist. The original link will go dead, and anyone else you tries to click on it will simply get an error message. Sadly there is no puff of smoke or small explosion, but the results are the same.