Warning: Use these directions are at you own risk and your mileage may vary.
Below is a list of Vista services (programs that run in the background) that when stopped seem to make Vista more responsive. There is a services icon in the control panel that will let you view, start, stop and change the default run behaviors for these and other services to manual or disabled. I recommend changing the load/run status of these services from automatic to manual instead of disabled.
Distributed Link Tracking Client
IKE and AuthIP IPsec Keying Modules
IPSec Policy Agent
KtmRm for Distributed Transaction Coordinator
Tablet PC Input Services
Windows Error Reporting Service