Open the run window, type in MSCONFIG, select the services tab and check the "Hide all Microsoft services" box. Then go through the list and figure out which you need and which you don't. Then select the Startup tab and do the same thing.
Also there's a program available online called Nlite. It's really cool, basically it takes your windows install disc and allows you to remove features and such from it, and makes a new windows install disc so you can install windows without all the extra stuff. It allows you to remove alot of features you couldn't otherwise remove like internet explorer, and Media player.
I have my PIII 1 ghz 256 MB laptop running windows XP quicker than my 3800+ 1.5GB Desktop by removing audio file support, media player, internet explorer, unused network features and a few other things I don't remember.
You can also try an overclock using this guide here Laptop Overclocking - LaptopLogic.com
but be veeeerrry careful since laptops tend to have very poor cooling systems. I know my old dell's is horrid.