I know we've all had times where a friend has trouble and you have to guide them through the process of doing whatever they are attempting to do, but my idea is:
Co-Op multiplayer mode in Fallout: New Vegas.
- No quests avaliable
- Only 2 people allowed (You and another player)
- Be over PSN or Xbox Live/ Whatever Windows uses.
- Just roaming around, exploring and killing things. Example: A friend needs a weapon, and you can show him/her where it is.
Basically, it's the same old wasteland, just no quests (unless you want to designate Co-Op quests just for it) and Only 2 people.
Think about it.