Switching anything off that you don't need/want will save memory!
First thing I did was switch that damn side bar with clock and stuff off, totally not needed IMO!!
I haven't really done more than that myself because I have 8 Gig RAM so it's not really an issue for me but for those with less, I'd look at microsofts site [link above] that telss you how to optimise Vista for better performance!

Injustice will be avenged.
Cofiwch Dryweryn.