The other location AV/SEP eats a ton of space is c:\Documents and Settings\All users\Application Data\Symantec.
This really is a mega pain for things like servers. Workstations I don't really care that much about since they have 120 gig hard drives of which is entirely C: drive. When you have servers that are based off virtual templates that only have 15 or 40 gigs for the OS, thats another story...