There was a mention of having a "headless" mini in a system. One possibility to enable this may be the VNC protocol and set of programs (open source, with some commercial versions as well it seems).
To try this, I downloaded the server and viewer for OS/X from
http://www.redstonesoftware.com - the download page has a link to realvnc.com to download the free version of the Windows viewer and server.
So far, it seems to work well enough for operating something like a music server remotely. I'm typing this message on a Windows laptop connected using VNC to my Mac Mini. It's not perfect - some niggles but so far it seems usable.
For those wondering why not just get a cheap LCD to connect to the Mini, I'd like to have the DVI output connected to a projector. Remote desktop capability means that the projector doesn't have to be turned on to e.g. play music or do other stuff.
You would want to have some way to have the server on the Mini start automatically when the machine reboots. Haven't looked into it yet but I'm sure there's a way...