Alas, the Foursquare conference, hosted by the Quadrangle PE fund, is an invitation-only affair. And the event, which kicks off tomorrow, is closed to the press except for reporters onstage to interview the stars. And those conversations don’t get released to the public.

That’s a particular bummer this time. Because the Quadrangle guys–who have had a rough year–had the foresight to get a lineup that includes GE (GE) CEO Jeff Immelt, who appears to be in the final stages of selling NBC Universal to Comcast (CMCSA) CEO Brian Roberts, who will also be onstage. Sure would be nice to hear what they say.

Another panel that piques my interest, if only because of the title: “Are Popularity and Profitability Correlated?” It features Twitter’s Stone, LinkedIn founder Reid Hoffman and YouTube co-founder Chad Hurley. And would-be moguls are represented by a start-up pitch panel that includes Dennis Crowley of Foursquare, the superbuzzy mobile service whose name has nothing to do with Quadrangle’s conference.

So once again, here’s the complete list of those you won’t be hearing from this week as they gather at the Plaza in Manhattan. Unless, perhaps, one of my more ambitious colleagues sneaks in–I’m thinking of you, Bobby MacMillan–and gets us a first-hand account.

2009 SPEAKERS
EMILIO AZCÁRRAGA President, Board of Directors and CEO, Grupo Televisa
DENNIS CROWLEY Co-Founder, foursquare
BARRY DILLER Chairman and CEO, IAC; Chairman, Expedia, Inc. and Ticketmaster Entertainment, Inc.
BRIAN DUNN CEO, Best Buy
CHARLES FORMAN Founder, OMGPOP
REED HASTINGS Founder, Chairman and CEO, Netflix
REID HOFFMAN Executive Chairman and Founder, LinkedIn Corporation
CHAD HURLEY CEO and Co-Founder, YouTube
JEFF IMMELT Chairman and CEO, GE
PAUL JACOBS Chairman and CEO, Qualcomm Incorporated
OLLI-PEKKA KALLASVUO President and CEO, Nokia
JASON KILAR CEO, Hulu
LESLIE MOONVES President and CEO, CBS Corporation
ANNE MULCAHY Chairman, Xerox Corporation
JAMES MURDOCH Chairman and Chief Executive, Europe & Asia, News Corporation
BRIAN PHILLIPS CEO and Co-Founder, Thread
DAN PORTER CEO, OMGPOP
BRIAN ROBERTS Chairman and CEO, Comcast Corporation
PAUL SAGAN President and CEO, Akamai
ERIC SCHMIDT Chairman and CEO, Google
IVAN SEIDENBERG Chairman and CEO, Verizon Communications
BIZ STONE Co-Founder, Twitter
HOWARD STRINGER Chairman, CEO and President, Sony Corporation
BEN VERWAAYEN CEO, Alcatel-Lucent
DAVID ZASLAV President and CEO, Discovery Communications

MODERATORS
MARC ANDREESSEN General Partner, Andreessen Horowitz
KEN AULETTA Author and Writer, “Annals of Communications”, The New Yorker
MARIA BARTIROMO Anchor, Closing Bell; Host & Managing Editor, Wall Street Journal Report, CNBC
JAMES CITRIN Co-Leader, Board & CEO Practice, North America, Spencer Stuart
DAVID FABER Anchor, Reporter, CNBC
MICHAEL HUBER Co-President and Managing Principal, Quadrangle Group
BECKY QUICK Co-Anchor, Squawk Box, CNBC
GEOFFREY SANDS Director & Leader, Global Media, Entertainment & Information Practice, McKinsey & Co.
JOSHUA L. STEINER Co-President and Managing Principal, Quadrangle Group
GEORGE STEPHANOPOULOS Anchor, This Week; Chief Washington Correspondent, ABC News

The tweens and twenty-somethings who flock to the site can still keep playing games there without paying. But the company wants to convince a few of them to start shelling out $5 a month for subscriptions that gives them access to bonus goodies and credits they can use for power-ups and other virtual goods. The credits will first be used on the site’s new “Hover Kart” game and will eventually be rolled out it to the rest of its 11-game portfolio.

Virtual goods + subscriptions + online games isn’t a new idea by any stretch. It’s really big in Asia, and there are several companies trying to port the model to the U.S. Some, most notably Activision Blizzard’s (ATVI) World of Warcraft and Disney’s (DIS) Club Penguin, are enjoying success on a large scale. I’m just noting OMGPOP’s foray for a couple reasons:

1) Gotta give the company credit for sticking to its guns, from an intellectual property perspective. The site has no problem taking games that have been successful for other people and offering refurbished versions of its own. “Blockles,” its first game, is a Tetris clone. And Hover Kart, its newest one, is an homage to Nintendo’s Mario Kart, which absconded with many of my hours in the mid-90s.

The folks at OMGPOP (and their backers, which include Twitter investor Spark Capital) think this is kosher because they’re not using the games’ trademarked names or characters–only their game play/mechanics (see: the Scrabble/Scrabulous/Lexulous imbroglio). But they’re already spending money defending a Tetris lawsuit, and it will be interesting to see what Nintendo’s legal team has to say about the new game.

2) Gotta give the company, and founder Charles Forman, credit for evolving. Two years ago, Forman was a Y Combinator graduate running a site called iminlikewithyou that was supposed to be some kind of flirting/dating/Facebook hybrid. It got glowing praise from the likes of Om Malik, but it was hard to see how it was going to amount to a business. So Forman changed direction and turned it into a game site.

Fast-forward to today and it’s still not clear if there’s a successful business yet–the site has sold a couple T-shirts, but that’s about it. But at least you can see how it might work. And compared to a lot of its Web 2.0 peers, that’s saying something.

Today’s example: OMGPOP, the casual gaming site formerly known as iminlikewithyou, which has raised a $5 million round led by Bessemer Venture Partners. Previous investors Spark Capital and Ron Conway’s Baseline Ventures re-upped, but not Netscape/Ning/“Project A” investor Marc Andreessen, who took a flier on the company last summer.

The site has raised a little more than $6.5 million to date. A conservative valuation would still make the company worth north of $10 million.

Why is it worth anything? The company, which began life in 2006 as a dating site, has a dedicated user base that logs some three hours a month on the site. But it’s still pre-revenue, as they say.

CEO Dan Porter, who took over for highly visible founder Charles Forman earlier this year (Forman is still at the company, cranking out games), says that will change this spring. He will be selling “premium” accounts/subscriptions, most likely for $5 a month, along with virtual goods (think collectible items, power-ups, etc.).

It’s possible that the site will roll out some kind of advertising at some point–Porter says he’s been testing some ad units with Google (GOOG)–but those would be ancillary dollars (or dimes).

Can that work? Maybe. Casual games–free or low-cost Web games that take little time commitment–appear to be doing well so far in the recession, even as traditional videogame sales falter. And a lot of people are hopeful that the  market for virtual goods–big in Asia, but limited in the U.S. to a handful of games and a few oddities like Facebook’s “gift” items–will finally take off.

Not interested in thinking this one through? Fair enough. Try playing the site’s “Balloono” game, a knockoff of the Nintendo classic Bomberman. I’m waaaaaay older than the site’s core 15-25 demo, but I’ve spent an embarrassing amount of time on this one.