The social media beauty pageant is about to send out its entry form.

The Austin, Texas, hoedown South By Southwest may be known as “Spring Break for Geeks,” but the big show comes in early July at “Moguls Summer Camp,” organized by Allen & Co. in Sun Valley, Idaho.

This prestigious media business retreat is known for many things: A-list business executives, luxury locales and, most importantly, as the petri dish for hatching deals.

In recent years, the Sun Valley event — Allen & Co.’s Arizona counterpart just wound up last week — has become something of a debutantes’ ball for the biggest names in tech.

This year’s entrants are likely to include:

* Foursquare — the social media networking Web site that allows you to locate nearby friends on your smartphone — has been closing deals with retailers to use the service to entice shoppers into the store with coupons as they pass by.

* Beyond Oblivion, the digital music service with smart search tools, just closed a $90 million financing deal with News Corp. (owner of The Post) and more importantly for its Sun Valley invite, Allen & Co.

In the resale department, News Corp. has hired Allen & Co. to shop MySpace, which according to reports may fetch $200 million and could be the talk of Sun Valley.

Past contestants from last July, Zynga, Groupon and Pandora, all got to present their business-case studies to the world’s big media, big finance and big tech.

Mark Pincus, who runs gaming site Zynga, known for Mafia Wars, Cityville and Farmville games on Facebook, had the opportunity to mingle with Hollywood’s finest, and things couldn’t have gone better for him. The executive landed on the Forbes billionaires list this week, and Zynga’s valuation now hovers around $7 billion, on the low end.

“I couldn’t be more impressed with him in this last year,” DreamWorks CEO Jeffrey Katzenberg told Fast Company this month. Katzenberg was asked who he’d most want to be at last year’s Sun Valley conference and quipped, “If I could be reborn today, I’d be Mark Pincus.” Pincus raised money from two Sun Valley regulars: PayPal founder Peter Thiel and LinkedIn’s Reid Hoffman.

Groupon’s CEO, Andrew Mason, attended Sun Valley last year, while company COO Rob Solomon just got back from last week’s Arizona retreat.

Groupon famously turned down a $6 billion offer from Google and is planning an upcoming IPO. The company, which organizes online coupons for the masses, values itself at $15 billion, according to reports.

Some might argue that Allen & Co. has a knack for picking the next big thing in tech. No one will reveal who picks the attendees, but sources tell The Post that you have to have built relationships with the bankers there before the golden tickets get sent out.

Demand Media’s Richard Rosenblatt, the former chairman of MySpace, has now launched three public companies. The latest is Demand, a Web content firm that raised $1.5 billion during its recent IPO. He told The Post, “I went down two years ago and it allowed me to meet a large group of CEOs and investors, and it’s been an important relationship.”

Rosenblatt said that the relaxed atmosphere of their events, which mix business and pleasure, helps foster good relationships. “It’s been extremely helpful. There’s a group of very influential people in an environment that is conducive to open conversation and dealmaking.”

While many firms have got a big boost from their Sun Valley appearance, some haven’t fared quite so well. The founders of Joost, the online video site that crashed and burned, were still waiting for their return invites a year later, and YouTube’s Chad Hurley seemed to disappear into thin air after he sold his site to Google. The rumor is that Hurley was shunned for not using Allen & Co. during the sale.