Recently I've been considering migrating many of my users back to XP (and have already done that for a few and my personal laptop).  As there are a few Vista features that I miss (I do like some of the changes to Explorer) I figured I'd see if I could do any tweaking to get Vista running a little better. 

The first and main thing I've done is turn off all the Vista GUI add-ons.  It's pretty amazing the difference it makes and since it basically looks like XP I don't really care.  So to do this here's all you have to do:

• Right click on the Computer icon either in your Start Menu or on your desktop and choose "Properties"
• Click on "Advanced system settings" over in the upper left
• On the "Advanced" tab click on "Settings" under the "Performance" section (at the top)
• Select "Adjust for best performance" and click OK

That should do it, after a few seconds Vista will revert back to a much more XP look and feel.  While I do miss some of the eye candy the boost in speed I've gotten is well worth it.  If you do give this a try I'd love to hear how it goes for you, can you feel a difference?