Getting a file revision

Hi,

This might sound like a novice question but anyway: I sometimes have a need to quickly recover an old revision of a file just to check something or copy some code from it. I would imagine having a command like:

git-getrev <filename> <commit> or something, and the file would appear in its path, or the git root directory as <filename>.<commit>

Is there an existing way to achieve a similar result? I can certainly checkout a branch, revert to that commit I want, copy the file, and come back to HEAD, but its not as quick.

Thanks, Bahadir