export one commit id from a repository

Hi,

I'm having a bare git repository on a server.

I'd like to be able to concurrently (multiuser) create tar files from certain commmit ids.

How can I do this most efficiently.

How I do this today:
- ssh to the server.
- clone the bare repository to a temp directory.
- checkout a certain version.
- remove the .git directory
- tar it up
- scp it to my local host
- remove the temp directory and the tar file

svn had the command 'export'

Thanks a lot for help or pointing me to existing scripts / tools.