There was a great link on /. in case you missed it which cited a great plan to rid/stay clean from spyware for Windows users. I've followed a very similar methodology with great success so far.

The one other tool I would suggest is WinPatrol 9.0. Which is a watchdog over critical system areas alerting you and giving you the option to allow/deny (ala Zone Alarm) access to those items. Good stuff.

Enjoy. Updated often, Immunize.
T