One of the most annoying thing in Vista is the UAC or the User Account Control. I feel like it always pops out every single time.

Actually it is not advisable to totally disable this feature of Vista. But you can use a program called TweakUAC(TM) to make UAC operate in QUIET mode. You can also completely turn UAC on or off.

Download TweakUAC here.

This is the description of the Quiet Mode Option according to their website:

This option does not turn off UAC; instead, it only makes UAC to operate in the quiet mode. In the quiet mode, UAC does not display the elevation prompts for the administrators. That is, when you attempt to do an administrative task, you will be allowed to proceed automatically, without prompting you to confirm the operation. All other features of UAC would still be enabled: the programs will run with the standard user permissions by default, and the standard users will still see the elevation prompts (the quiet mode applies to the administrator accounts only).

Download: TweakUAC