What Should I Do to Celebrate My 50th Birthday? [SURVEY]

In four months I turn 50. It's time to start planning. I DO NOT want a big party. Eck no! I don't want to go to Las Vegas. That's not my thing. I've already been to Mexico. Any ideas?

What would be something really cool? Something I'd remember for a long time, or would be incredibly fun with some close friends?