Neo geo us or jap

neogeo has no country lockout at all, however the hardware decides the language.. all games (US, euro and jap) will run in japanese on a japanese neogeo, and all games will run in english on an US neogeo.
About the Game Cube thing .. I bought a Game cube from an asian site that has a switch on its back to change from Japanese to US, works very well with no problems at all.
finally, a company that had the sense not to put a country lock-out in place...

The Neo Geo really isn't any different from the SMS, Genesis, Saturn, or Dreamcast in this sense, in that it's left up to the developers. If Neo developers wanted to create a cart that would only run with systems of one territory, they could do so. Of course, this would be a pretty stupid thing to do considering the high production cost and relatively low demand for Neo games; it's a better idea to be able to relabel leftover stock and try to sell it elsewhere...