1. To appear in someone else's photo without thier permission, often pulling a stupid or offensive pose. Best done in a dark club where the deed can't necessarily be detected until the photo is viewed, by which time a speedy escape has already been made.

2. To jump in front of a camera as someone is taking a picture of someone/thing else. Worsks especially well on tourists in foreign cities.

Often causes frustration and annoyance to the victim(s) but great amusement to the perpetrator and thier peers.

When you eat dirt for the first time and leave your family to build a shack in the woods

On facebook, to tag yourself in a picture that you are not in without the permission of the owner. Therefore, the picture shows up as your own.