A reader emailed me a question about running under a non-administrator account in Windows today, which prompted me to do a little MSNSearch-ing. That lead me very quickly to Aaron Margosis's excellent blog. If you are interested in how you can get by in life without having to run every process as an admin, check out Aaron's post on RunAs, and then read the rest of Aaron's recent entries. Check out the nice utilities he's put together, MakeMeAdmin and PrivBar.
If you're thinking to yourself "why doesn't Microsoft build this stuff right into Windows", rest assured that you are not alone. Back at the 2003 PDC, the security team talked about apps running under least privilege. Keith's April 2004 article was based on older builds and plans have changed somewhat since then, but it's definitely on the list of areas to focus on for Longhorn.