SnapMeNow, a web app, uses your computer's camera to take a picture that you can send to up to 100 recipients via a hyperlink. That image self-destructs Snapchat-style after an interval of up to 10 seconds. When a user receives your Snap, they see a little clock filling up next to the picture, and when the picture disappears, they receive a simple message telling them that the Snap is no more.
Of course, a Snap on your desktop is a lot easier to capture, save, and manipulate than a Snap on your iPhone (as above), so, before the parade of ephemeral nudes, bong-rips, and occult homicides begins, remember: Snapper beware!