I've noticed google talk keeps all the "upgrade" installers:
In the GT folder (C:\Program Files\Google\Google Talk), are 2 redundant folders 'googletalk-1.0.0.100' and 'googletalk-1.0.0.104'
both including a 'googletalk-setup-upgrade.exe' installer.
Taking up a tiny 1.5MB each, so if it could be added to cleaning that would be good.