upload-pack packfile caching

I was wondering if it would be of general interest to have upload-pack
take an option to cache packfiles.  Unless I am mistaken, every clone
on a git server will recreate the same packfile until something new is
pushed into it, correct?  I thought it might be a good idea to pass an
option to have it cache the packfile that is created if
create_full_pack is set and re-use it until the repository is updated.
 If I patched upload-pack to do this, would there be any interest in
it?

Scott