For any who don't know of the game Minecraft (download it at www.minecraft.net), it is a game in which, essentially, you can create pretty much anything by destroying and placing blocks and by crafting and smelting objects. It's addictive, in a word.
Now, there is a multiplayer version of this - where it is possible to make much larger and more impressive things due to increased manpower - and some endeavouring people have taken it into their hearts to do something amazing.
Get this: they are building Middle-Earth, down to every last detail.
The Shire is almost completely finished, Bree, Weathertop and Rivendell are done, and they are about 3/4 of the way through Moria. Annuminas is also being worked on. They are always looking for new players, and especially those with a love and knowledge of Tolkien's world.
Have a look at http://www.minecraftmiddleearth.com/.