According to Kalen Delaney (buy her book) you can safely disable these services on Server 2003 running SQL 2008:
Alerter, ClipBook, Computer Browser, Messenger, Network Dynamic Data Exchange (DDE), Task Scheduler
I am not in front of a 2008 server but some or all should still be relevant.
There are no special teachers of virtue, because virtue is taught by the whole community.
--Plato