There are a number of ways you can remotely administer and control a mac OS X computer. macminicolo.com's parent has successfully used these applications for a number of years. In addition to the UNIX command line there are a number of packages including (you must purchase your own remote control software-- we do not provide it):

VNC

We have a full VNC tutorial here.

Timbuktu from netopia.
macminicolo.net will install an evaluation copy of Timbuktu, good for 30 days on any mini that indicates they would like us to do so. You can get a free evaluation copy from here.