(posted: 6/8/2005 6:24:20 AM) Simple - plug up to 4 games into your arcade unit, and turn the arcade on!
That said, if you don't have a cabinet to plug the motherboard into, you can try to make your motherboard into a "console". This is a complex process, but basically, you'll be soldering TV and Audio output jacks onto the motherboards. You'll also need to make connectors for joysticks. It's not easy, and really getting into the details is beyond the scope of this question/answer. I'd look to www.neo-geo.com or other similar sites if you'd like help doing something like that.
As a side note: The Neo Geo motherboard is actually 2 boards, and connects to a JAMMA+ connector (-5V is unused). The reason for this is that the Neo needs more buttons - 4 for each player, plus a select game button. So, while you can't plug the motherboard into "just any" arcade cabinet and expect it to work, many have done the conversion. Check www.hard-mvs.com for pinout details, and how to make the proper harness.