WH40K Vassal is a program that lets you play WH40K tabletop over the internet with other people.

This is Vassal the base software:
[url=http://www.vassalengine.org/]

And here is where you get the Warhammer 40k module for vassal:
[url=http://vassal40k.tripod.com/]

You still need the rulebook and the codex of any army you plan to use but that is it.

Fallen Muse and I have already had an interesting game using this over the internet and I am up for anyone else wanting to play or wanting to learn more about this.