if you plan on playing the golf games i recommend not having anything (ie the spinner) in line with the trackball. and you mentioned placing the tb in the "upper" middle. make sure you're not to close to the screen. a couple of my friends manage to hit the screen on actual machine and i'd hate to see what would happen if the tb was closer to the screen. of course, if your friends don't take the running start like mine do, this may not be an issue.