Some of the Windows 7 services I don't really need. Especially the new Aero-Desktop manager and lot's of Tablet-PC, Windows Firewall, Windows Defender, Windows Media Center, Mp3 and printing services. You can save up to 100 MB of RAM with disable everthing you doesn't really need. Here are some automated tools and tutorials:

1. www.thewindowsclub.com/smart-a-utility-for-tweaking-windows-7-vista-xp-services

2. www.blackviper.com/2010/12/17/black-vipers-windows-7-service-pack-1-service-configurations/