Keygasm
It's a physical reaction that a person has when they get over stimulated or excited when typing, often when someone is in the act of Instant Messaging. It causes the typer to make several mistakes and become flustered, eventually just feeling exhausted and unable to continue typing.
Jen: What happened when you were talking to Craig in the chat room?
Cheri: I got so excited that I completely keygasmed and finally logged off.
Cheri: I got so excited that I completely keygasmed and finally logged off.