So I'm roaming through the wasteland and I spot a shack door in the side of a rock. I get closer and it says I have discovered Vault 108. I was like "sweet some people to trade with" (I was carrying a ton of stuff and needed to offload or I would have to have gone back to megaton to do it and abandon the rest of the exploration). So I go inside and find the vault door open, ok strange, I keep going. Farther in I find that the interior is all scorched and torn up, even stranger, I keep going. I enter the main vault area and encounter a guy with a lead pipe. His name was Gary 33 and all he would say, while he tried to pummel me, was the name Garry in different phrases. I pull out my plasma rifle and quickly dispatch him. I move on and find two more of the vault residents, Garry 31 and Garry 34. All they say is "Garry!", "Ho ho ho Garry!", "HA! Garry!", "Garry?", "Ah, Garry", "Garry! Garry! Garry!". I had to plasmize about 5 of them before I decided there was nothing for me there and left. I was like WTF?! Anyone know what the hell that just was because I sure as hell don't.

Wrong forum. You want the Fallout 3 Spoilers forum, I think.

All of the Vaults were social experiments of one kind or another. Vault 108 was given a cloning machine and a lot of problems - not enough power, too many weapons, too much authority in the overseer. Apparently it didn't work out well, because the only people left in it are clones of Gary, probably one of the original Vault Dwellers who ended up killing the others.