The Bay Area, ground zero for apps that will change the world and the investors who finance them, is one of the least charitable places in America. The Chronicle of Philanthropy ranked the 50 largest metropolitan areas. San Francisco was no. 45 on the list.

A new viral sensation is sweeping our nation's billionaire technologists: Daring their rich friends to either donate $100 to ALS research, or dump a bucketful of ice water over their heads. The latest mogul to save a hundred bucks is none other than our frugal friend Mark.

Now that techies are hacking homelessness through code and GoPro chest cams, real organizations are recruiting tech's help (dollars) with words the Valley will understand: "Disrupting Poverty." [Photo: @ProfJeffJarvis]

Meet Joe Gebbia. Joe founded Airbnb with another guy in 2008, and still works there. Airbnb is doing well, and maybe someday it'll be a valuable public company. For now, would you like to pay $2,500 to Skype with Joe for 60 minutes?

Philanthropy today: Larry Page, the Google co-founder with $32 billion and little record of altruism, says he'd prefer another tech billionaire inherit his estate instead of leaving it to charity.

When Twitter, one of San Francisco's flagship startups, threatened to ditch the city over tax complaints a couple years back, the city caved. Twitter received a giant break, in exchange for a promise to help the struggling neighborhood around its office. Did it? Sort of.

CharityBuzz has announced the winner of the most expensive cup of coffee you've ever had in your life with Apple CEO Tim Cook. A newcomer known only as "a********s" came out on top with $610,000 bid. Congratulations, Mr. assssssss?