Bill Gates seems to be enjoying his semi-retirement.

At the TED technology conference in California, Microsoft's (MSFT) Chairman just let a bunch of live mosquitoes go into the audience.

From Twitter, we gather that Bill was talking about malaria prevention, one of the causes his Bill & Melinda Gates Foundation is pushing.

"No reason that only poor people should get malaria," attendee Tara Hunt paraphrases Gates as saying.

We like eBay founder Pierre Omidyar's reaction the best: "That's it, I'm not sitting up front anymore."