Creating binary gems, from source gems


So here is my question:

Is there an easy (read automated) way to take a gem (that requires a
binary compilation) from a properly configured development/build
machine and create a binary gem?

I have production servers that will not include a C/C++ compiler or
other development tools – I would like to use gems for my packaging
and deployment. I can of course do this by hand, but it seems like a
common enough task (or will be as ruby pushes more and more into the
mainstream), that others may have already encountered (and solved)
this problem.

If not would this feature be a welcome patch to gem? (or is it already
there and I did not see it)