^exactly
Just google the services before you get rid of them to make sure you're not taking out anything you actually want to start on startup.
Also, disable disk indexing. Right click on any HDD's connected to your computer and select the option for "Properties". At the very bottom of the Properties menu you will see a check mark next to "Allow Indexing service to allow Indexing of this disk...", uncheck that. It will speed up your computer a bit, and free up space on your hard drive.
Another thing you can do is disable system restore. The only downfall to this is that you won't be able to turn back time if your computer shits the bed. Anything for the extra speed. ;]
Also, goto Start and select "Run...". Type "services.msc" in the text box and hit the enter key. This will bring up a list of services that are running on your computer. I would suggest running down this list on the following website and disabling many of them.
http://tweakhound.com/xp/xptweaks/supertweaks6.htmHell... just goto google, and type in tweakguides.