Screwdriver handles are shaped so that a wrench can slide over them for more torque.

[zombola]

http://i.imgur.com/2mcDBXB.jpg

[The Cobra]

Interesting concept although I don`t know how much you`d actually use them. I`d think if you need more than a little torque you`d strip the head of the screw before you`d loosen it because keeping an equal pressure on the head would be difficult.

[steveOtoo]

They do make impact screwdrivers for those nasty little situations............

[bigbadbrother]

Snap-on screwdrivers have something like this but it's not the handle it's part of the blade. far better.

[Nostradamus]

I have done it before. Too much torque and you just strip the head like already mentioned but works great for in those spots where you can get a screwdriver on it but don't have the room to turn your hand. One of those ratcheting box end wrenches work best. The biggest problem is trying to get the screw started when re-assembling something :)