Well it isn't Go, but Go Moku, but if you're a fan of one, I imagine you will love the other. They are both games that require good strategy and intelligence (similar to chess).

Take a look at it and tell me what you think... You can play against the computer, two players on a single computer or over a network (with a chatroom enabled) with innumerable observers who can watch and join once the current challenger quits.

The game is just over the limit, so it's attached in a spanned zip (just unzip the second file).