+1. It's something similar to Linux when it asks for root access, except it's overkill. I leave mine on though, for the 'extra security' it is supposed to provide by not allowing malicious code to execute system stuff that easily. Plus I hardly boot into Vista
Mine is disabled on my laptop. But I have it enabled on my mom's laptop (since she isn't a power user).
UAC isn't just a "continue" button you press, it's a whole level of added security.
If you are a novice, keep it enabled, if you aren't switch it off, same rule applies to system restore, don't disable system restore because a tweak guide told you to.