From my barely posted to
Here is a good article on MSDN about running as a non administrator. I personally never run as an admin (well accept on virtual images) and it is not as difficult as you might think.
The good thing is as a developer, I don't have to worry if my code will run if the user is not an admin because I have unit tested the crap out of it that way.
Keith Brown of course has some good tips as well.