"Life is meaningful"?

I have a short yet serious little question for everyone. I was on my bus home from wine-night at an acquaintance's apt last night, listening to Jason Mraz on my mp3 player, and as often happens for me on the bus, it inspired some lyrics for me. It also brought up this question (no, it wasn't the champagne!):

What makes a life "meaningful"?

Post your thoughts as a comment - would love to hear from you.