Online coupon site Groupon just opened up a new office, in Silicon Valley, Calif. , which will also houses its latest acquisition, mobile develoment firm Mob.ly.

Addtionally, Groupon has announced its new “G” rewards program. Initially inviting 10,000 to try G, and invite four of their friends, to do so, Groupon is giving away points known as G’s for various Groupon activities. It can be as simple as looking at the daily deal. Once you have the right number of G’s you can exchange them for discounts in the site’s Local Marketplace or even get a daily deal at no charge.

Those who register for the rewards program also get invitations to local Groupon parties planned for the future, and get to take part in G-oodies, providing free giveaways to a few folks who buy Groupon deals.

Quite a bit of this is unformatted, and a little tongue-in cheek, as with the G-oodies parties that promise to feel like a 7th grade formal. Here are more details from the Groupon blog.