[lupatus]

For quick decision-making based on limited information when your opponents may be actively lying to you and colluding against you, see Diplomacy[1].

[1] http://en.wikipedia.org/wiki/Diplomacy_(game)

[iktorn]

http://www.playdiplomacy.com/ :)

[lupatus]

gamesbyemail.com also has a nice diplomacy interface.