I quite like UAC myself.
It annoyed me at first, but I got used to it, and know when to expect it on a day to day basis now... though I'd still appreciate a "safe list" type thing, where I could add those programs that need to be run as admin, and not bother me with UAC each time.
Anyway, I found it handy last week, as I went to asus.com a few times to check for bios updates.
I noticed my network meter shoot up when I visited the page, and after a few seconds, UAC popped up, warning me that something was trying to install, so I had the chance to cancel. Happens every time I visit asus.com, even just now as I tried again as a test.
Nice to see UAC working, and showing that it can block unwanted installs. I guess if a virus/spyware made its way onto my system, and tried to run, I'd be alerted by the unexpected UAC prompt.
Vin.
EDIT: btw. what would happen if I'd visited asus.com, on XP, or without UAC enabled. Would this code have automatically run/installed? Or would it have been blocked anyway, and I'd have known nothing about it?