Investors Bet on Another Real-Time Start-Up. Next Up for Hot Potato: Product, Users.

Here’s a good way to get your hands on scarce venture capital money: Create a start-up geared around “real-time” sharing and conversations.

That’s the core of Twitter’s pitch, of course, and it has helped the microblogging service raise $155 million, a $1 billion valuation, and forge partnerships with Google (GOOG) and Microsoft (MSFT). Not surprisingly, investors are looking to place money on related bets, from search engines that parse real-time data to location-based social networks with real-time updates, and even real-time photo-sharing sites.

The newest entrant: Hot Potato, a buzzy start-up that’s supposed to let users converse about a particular event, whether they’re attending it in person or watching from afar. When it’s up and running, that is. The five-man crew doesn’t have users or a product just yet.

But that hasn’t prevented the Brooklyn, N.Y-based company from raising about $1 million, sources say, in a round led by First Round Capital and RRE Ventures. A group of smaller investors, including Betaworks, the incubator that specializes in real-time companies, and Ron Conway, the angel investor best known for his Google bet, are also backing the company.

Hot Potato is led by Justin Shaffer, an eight-year veteran of Major League Baseball Advanced Media, pro baseball’s well-regarded Web unit. Shaffer has recruited three other MLB.com employees (one of whom subsequently left to get an MBA at MIT) to join him.

Shaffer wouldn’t comment about his funding round, but was willing to discuss his start-up’s general plans. They are finishing an iPhone app and plan to submit it to Apple (AAPL) in the next few weeks, he said, and will open their doors once that’s approved.

The big idea is an interesting one. People are already using Facebook and Twitter to converse about events in real time–think about Barack Obama’s inauguration, or Balloon Boy, or last night’s Yankees-Angels game.

Shaffer’s critique of those platforms, though is that “they break at scale–there’s no good way to filter the chatter so that  you, your friends, and a group of strangers with something relevant to say can all connect. Hot Potato, he says, will offer a “curated stream” in real time of all the data coming out of the event in real time. What we’re really focused on doing is bringing together the entire audience of an event, whether they’re at the event or watching at home.”

Business model? TBD, of course. But there are a couple of obvious ways to go. For instance, Shaffer thinks people who opt-in to a particular conversation–say, about an NFL game or a U2 concert–would be okay with seeing “in-stream” ads, as long as they were relevant.

But that’s a problem that’s best tackled once the service is up and running. We’ll check back then.