Just in case any of you havent heard yet, XPORT, the writer of many of the best xbox emulators, is in the process updating MAMEoX. He is going to add virtual memory support for MAMEoX and is also looking in to finally implimenting light gun support. If all goes well, the VM support could pretty much mean the end of KAWA-X and make MAMEoX the onestop emulator for arcade games.
It actaully has been released, but still in beta. probably in a couple of weeks it will be more stable