Quick, there's free lunch in Mountain View! And, tonight, a party for the Commonwealth and a very special concert — all in today's Valleywag Calendar.

• Mozilla, the maker of Firefox, hosts a Lunch 2.0 today at noon. Free software, free food, woohoo! [Upcoming]
• The Commonweath Club throws a holiday party for their young professional group Inforum. It's at Harlot in SoMa at 6:30. $20 for nonmembers, $10 for members, and new members who sign up at the door get in for free. [Commonwealth Club]
• The Spice Girls play at San Jose's HP Pavilion tonight. Will the Valleywagger known to spout lines from Spice World be there? The show appears to be sold out, so you'll have to buy resold tickets online. [Craigslist]

Got a to-do that's a must-do? Send it to calendar@valleywag.com. Check out more events on our Google Calendar: