What's that tool called?

[greg.rocco at gmail.com (Greg Pallett)]

Welcome to another exciting round of *'What's that tool called?!*'
I'm looking for the name of the tool that is like an impact screwdriver.
You wack the end of it with a hammer and that turns the bit a 'lil.  Great
for getting really stubborn screws out!
I'd like to know the 'technical' name for it, it makes it so much easier to
ask for it at hardware stores.
The goal is to take off my foam wing and seal up some leaks I suspect are
coming in that way.

Thanks.

GP

-- 
"Fatal mistakes rarely happen, but funny things often do"