Run restricted programmes from guest a/c

You can run a program as a different user without logging out and back in again. Right click the icon of the Program, select Run As...... and enter the user name and password you want to use. This only applies for that run. The trick is particularly useful if you need to have administrative permissions to install a program in domain controlled network, which may require. 

BEWARE :Note that you can have some fun by running programs multiple times on the same system as different users, but this can have unforeseen effects.