Mark Zuckerberg: I Just Had a Baby ... Here's $45 BILLION, World!!

Most dads hand out cigars ... Facebook founder Mark Zuckerberg celebrated the birth of his daughter Max on Tuesday by handing out a freakin' fortune to charity.

Zuckerberg and his wife, Priscilla, announced the birth on his FB page with a heartfelt letter to their newborn. In it, they say she gives hope for the future, a future they hope includes "advancing human potential and promoting equality."

To do his part, Mark and Priscilla pledged to give away 99% of their FB stock -- worth $45 billion right now -- over the course of their lives. He doesn't specify who will get the dough, but says it'll go to people who improve "this world for the next generation."