I typically don't like these sorts of summaries, since there's more to a person than what they can think of on the spot when asked to summarize themselves. That, and people like to write about who they wish they were, and not really who they actually are. I think the best part about meeting someone is learning what makes them unique.
With that said, if I had to describe myself, I think I would fall under a couple of categories:
-Likes to find the humor in everything in life
-Likes to try all kinds of new activities and experiences
-Devotes himself to his hobbies and passions
-Is open minded in many regards, but likes to view the world logically and rationally
-Tries to live life care-free with as little worries as possible.