runas for Unix-like Systems
Download these two files, and place them in /usr/local/bin. Chmod them to 755, and chown them to root:root.
Then, perform the following command:
runas -u someuser command
runas -v command
runas -v -u anotheruser command
This is useful for starting scripts as other users, with a full GUI.
By amending line 68 of the "runas" script, you could make this be your "standard" way to run virtual machines (
runas -u virtualbox virtualbox)