oh god.. what happened here. what I meant to say nymox, is that they are an awesome fish, but unless you intend to keep only one, they would do better in a larger tank- 2ft long at minimum.
Zev, I have 3 GBA's in their tank as well as a bumble bee goby and they could care less about the other fish.
I have seen the males flare at each other, and that finally led to me having only one male in the tank.
Now I have 3 females, and will look at getting one more and then another male to make up for the last one that jumped when i was away.