Get off

[bobjenkins]

I've heard it before, but I've always associated it with "tongue in cheek", like being funny.
:)---

[hermit]

Naturally quite common in Canada, somewhat less so in the States:

"You've got some cheek!"

"That's a pretty cheeky thing to say!"

Etc.

[Charles]

I should point out to American ears both sentences sound very strange. It is British English slang.