If you haven't played it then you need to. It's an addicting game where you can build anything you want during the day, and at night time "creeps" come out like Zombies, skeleton archers, and a few other weird things. The game is highly moddable so you can add almost anything you want from world war 2 vehicles to modern day weapons. The stock graphics suck but you can download HD texture packs that make the game look really nice. Also the game can be "tuned" down in the options section so it can be played on any PC or laptop.
You just buy it at minecraft.net and download it. It use to be 18 bucks but I heard the price went up after they released the newest version. I'm not sure what it is now.
Also a member here (zen1911) was cool enough too start and run a server for us, so if you guys ever want to jump online with us and see whats it about just download the game and click multiplayer and type in the IP.
Here is the name, IP address, and dynamic map web address of our server.
AR15 Republic Minecraft Server
The dynamic map is pretty cool if you put it into 3d mode and zoom it. To bring up the map options just hover your mouse over the right hand side of the webpage.
Oh also last thing. We have the AR15 server locked up so the general public can't get in. We are only accepting ar15 members and those they can personally vouch for. So to get in just add your minecraft name in this thread and I will add you to the list of people allowed in or "white listed" as its called in minecraft.
There are a bunch of us in there now workin on an underground city. You guys should jump in and check it out.