Stamp Git commit id into file during build process

Hi, I am in the process of migrating from Subversion to Git. One thing I am unsure of is how to stamp the 'version' or 'commit id' into a file as part of a build process.

With subversion I used the SubWCRev tool from TortoiseSVN (http://tortoisesvn.net/docs/release/TortoiseSVN_en/tsvn-subwcrev.html).

With Git I imagine that I'd like to put a copy of the current commit id (either the full hash or a truncated version of that) into a file which then gets included into the program source code in some way.

Is there a recommended way of doing this with git? Perhaps with something similar to SubWCRev?

Currently I am thinking about using "git log", and grepping the output in some way so that I just get the hash.

Thanks in advance,