And keeping the software up to date? Deploying over GPO allows easy uninstall of old versions and installation of new versions should a patch come out, like say Adobe Reader 9.3.
I have the GPO at the top level of my OU and then specify which software gets installed to which computer by hostname. Then following a re-image or machine replacement, the user gets the software they need.
Using Group Policy to deploy software to select computers - 404 Tech Support