I am pretty cheap with buying software, but I have to say that paying to upgrade my VMWare Fusion from 2 to 3.1 did wonders for my machine. I need to have VMWare for work applications and the V2 was a dog particularly with a resume after suspend. Wish I wasn't so cheap when it was on special for $10,b tu just wanted to share.
(and in case you are wondering, No I do not work for VMWare, EMC or have any financial interest of it.)
Macbook Unibody 2009 /G4 1.8/ 1G / 200G : Sawtooth Media Server / iPhone 3G, Mac OS X (10.6.6), iPod Mini :TiVo S2 240G : Tivo HD: Retired Apple II/e: 2 Blueberry G3's