to all friend list. commonly used as a message heading on xbl.

Someone who used to be a potential girlfriend/boyfriend, but no longer is.

Take a flying leap
(from/off a tall building)

TAFL is used on Xbox Live to signify that the message is to all of the users friend list. TAFL is To All Friends List.

A not-so-common internet acronym that is becoming popular amongst some teens, it stands for "tears apart from laughter."