I love TweakXP .net
Last night, I posted about the new version of TweakXP for Windows Server 2003. Well, my computer is running TONS faster. The biggest performance increase came from the “Enable Core System Performance” tweak, in conjunction with offloading my paging file to another disk. Another tweak that really increased startup performance was the “Speed up Network Access” tweak in the “Windows Tweaks II” section. Since I'm on a cable modem, startup would often take a long time while the network got its bearings and pulled an IP from the router. Now startup is nearly instantaneous after login.
I woudl highly recommend getting this product, even for server farm installations. It's hardware and system tweaks will help your web servers and database servers increase their performance exponentially.