Ludic Labs, a social media tech development firm, has picked up $5 million in a round of funding led by Accel Partners; KPG Ventures and a number of undisclosed private investors also participated in the round. Founded in 2006, the San Mateo, Calif.-based startup has been in stealth mode, but today it unveiled Diddit, an online community that connects members around various goals and experiences.

Members create multimedia profiles that highlight activities in categories like extreme sports, dining, and entertainment; they set new goals and check off the items once they’ve “diddit.” They can promote upcoming events, and the Diddit team also creates lists of activities in relevant categories. The company says the site amassed more than 10,000 registered users from a short beta, and offers over 300,000 activities to browse already. Diddit is similar to Going.com, the social network centered on events and activities; both sites are ideal channels for nightlife, travel and event-based advertisers.

In this economy, it seems a bit frivolous to launch an ad-supported service—particularly one that will rely on advertisers targeting discretionary income—but Ludic Labs’ founders Brian Totty and Paul Gauthier have experience running a new media startup in the midst of a downturn: they previously founded Inktomi, a search technology firm Yahoo acquired after the dot-com bust.