Miller appears to be the first member of Congress to hold something akin to a press conference in this virtual world, which is operated by Linden Lab and boasts its own currency and a population of more than 2 million "residents."
The event, which lasted about half an hour, took place in a virtual adaptation of the Capitol building on an island in Second Life. Instead of a neo-classical dome, the virtual equivalent featured an open-air amphitheater, mammoth video screens and an orange sky above.
"It's going to develop into an important forum for members of Congress of both parties," predicted Miller, who has represented the district northeast of San Francisco since 1974.
He also used his time to plug "100 hours," the name for the Democrats' plan to spend next week enacting laws such as raising the minimum wage to $7.25 an hour.
But the event wasn't a true Second Life-style press conference. Instead of typing responses to questions, Miller read them aloud via an audio broadcast that was piped in through a process like a telephone conference call. It also appeared as though an aide, rather than Miller, was controlling his Second Life identity, also known as an avatar.
Miller wasn't the first politician to venture into Second Life. Mark Warner, a former Virginia governor and possible Democratic presidential contender in 2008, gave a virtual interview last year. Some Dutch politicians reportedly have done so as well.
Before Miller's Second Life avatar showed up, a C-SPAN broadcast of the House of Representatives' swearing-in ceremony was reproduced on two oversize virtual video screens. The virtual Capitol was developed by Clear Ink, a marketing firm that sponsored Thursday's event.
In aprepared by CNET News.com that rated technology votes, Miller received a failing grade of 42 percent. That's largely because of his votes on morality hot-buttons such as opposing Internet gambling, approving a federal investigation of Grand Theft Auto, and siding with restrictions on social-networking sites like MySpace.com.
CNET News.com's Dan Terdiman contributed to this report.