Have a group of friends, but don't know what to play?
Use this tool to get a list of Steam games that everybody has in common.
You can use tools such as steamidfinder.ru to find Steam IDs, or copy one from the end of a Steam profile page URL
e.g. http://steamcommunity.com/profiles/76561197998981192/ or http://steamcommunity.com/id/shoffing/