Every month, the Hadoop user group meets to discuss Hadoop, big data, cloud computing and more. The event starts with a time to network and socialize over food and beer. Typically the food and fellowship is followed by 2-3 presentations.
The SF Bay OpenStack developer meet-up occurs twice monthly. They are a group of free software developers who are passionate about working together to help make the OpenStack project a success and they are sponsored, in part, by Yahoo!.