[link|http://www.downloadsquad.com/2007/06/03/temporarily-disable-uac-in-vista-without-rebooting/|Download Squad] has a pointer to [link|http://www.tweak-uac.com/what-is-tweak-uac/|TweakUAC]. (I found it via [link|http://blogs.zdnet.com/Orchant/?p=464|Office Evolution], via a search on [link|http://blogs.zdnet.com/microsoft/|MJF's Blog]).

Caveat emptor, and so forth.

Cheers,
Scott.
(Who is happy he has no interest in running Vista.)