Twitter co-founder Biz Stone took the stage at Fortune magazine’s Brainstorm Tech conference late this afternoon and was greeted by that old chestnut: When is Twitter going to make some simoleons?

Fortune’s Adam Lashinsky, who interviewed Stone (the pair are pictured here) posted a poll about that and a few other topics (the audience preferred Facebook to Twitter by about three to one, for example), and then asked a question he said was on the minds of many in Silicon Valley:

“Why the hell aren’t you guys making money?”

“I think that’s a legitimate concern,” said Stone. “We need to focus on value before we focus on profit.”

But, he added that the San Francisco-based Twitter was ready to show some commitment to revenue this year.

Oh dear, what will BoomTown have to gripe about at Twitter now?

Because–aside from the lack of a business model–I must confess I like Twitter an awful lot and find it extremely useful!

Earlier, Stone made the salient point that Twitter was just in the first innings.

“We have a lot of growing to do,” he said. “In general, we feel we are about one percent into the growing of Twitter.”

One more important issue than money-making, he noted correctly, was that the level of engagement at Twitter is not as high as the level of awareness.

“We just have to position our product better,” said Stone.

Of course, Lashinsky had to ask about the recently stolen documents that a hacker nabbed from some Twitter employees’ personal accounts.

Stone said that there are “unpolished notes,” which only “give you an idea of scope we are thinking of…the idea is that we are thinking big.”

Lashinsky asked if Twitter would sue either TechCrunch, which published some of the stolen documents, or the hacker who stole them.

(My first thought: Let’s all pray that TechCrunch will avoid touting that navel-gazing nonstory into the weekend.)

“I don’t know,” said Stone diplomatically, since TechCrunch’s Michael Arrington was sitting right in the room. “In general, we have a responsibility to look into these things and see what makes sense.”

Then, it was pretty much back to business models, and Stone seemed open to a lot of them, as long as they were not forced on the innovative digital darling.

“We want to develop a revenue model that is baked-in…and is not something that is tacked on,” he said.

Some ideas: Advertising, of course, as well as commercial accounts and verifying brands.

“We spent a lot of 2008 trying to get ahead technically of the unexpected popularity,” said Stone. “The very, very high level [of what Twitter needs to be doing] is to add more value to users.”

That means more focus on adding new features, such as a reputation system, better discovery and more explanation–for David Letterman, for example–of exactly how Twitter can be used.

And yes, making money. Stone noted that Twitter wanted to change the world too, and the best way to do that was to make “tons of money.”

“What we don’t want is to become that child actor that grew up all freaky,” he said, noting a Ron Howard development cycle was Twitter’s goal.

All hail Opie Twitter, oops, Taylor!

[Photo credit: Brad Markel for Fortune]

In BoomTown’s ongoing quest to overdose on tech conferences, I traveled south of San Francisco last night for Fortune magazine’s Brainstorm: TECH conference.

Run by David Kirkpatrick, it’s well done and a great place to run into a range of techies from Silicon Valley, as well as talk to more creative thinkers on where tech is going.

I was there to be on a dinner panel with fellow bloggers Om Malik of GigaOm and my favorite geek to tease, Robert Scoble, of Scobleizer. Fortune’s Adam Lashinsky moderated.

It was an interesting panel about a range of topics, from Yahoo (YHOO)–Kevin Kelly was bored, bored, bored with that topic–to the looming economic pressure that the digital industry is about to experience (a bummer, but entirely true).

Here’s the video: