Just to chip in, for VirMin I used a script based system to describe the game setup. As part of that, I load map sections on the fly so I can create anything from one huge map sheet to maps based on a mosaic of transparent sections.
You can catch of a screen shot of that here:
http://www.geocities.com/tzircher/tcom_gallery.htm
If you all have any questions, I'll try to field them. I'm a long time war game and RPG fan and I've written my fair share of books and utilities for wargaming (battle engine, tactical and strategic rules, PBEM game aids, etc.)
No, I'm not looking to join any teams, but I do like helping folks when we have similar interests.
--
TAZ