MADISON, Wis. -- The popularity of hybrid automobiles continues to grow -- a fact evident to visitors at this weekend's Dane County Fair, where the annual Hybridfest Green Drive Expo is taking place.

But despite the increase of hybrid sales, the vehicles are still largely seen as a niche vehicle. Eric Powers, the event's manager, said he has a long history of niche vehicles.

"I've had everything from a '70 LeMans that I rebuilt to a 1952 DeSoto. I'm a car guy at heart," Powers said.

Powers is still a car guy, but he said he's not interested in bringing back the DeSoto. He's now only interested in newer, greener ways of getting around and of bringing the Hybridfest message to the public.

What is the Hybridfest message?

"It's hybrids, it's propane vehicles, it's biodiesel, it's electric cars, electric bikes, it's everything," said Powers.

The message was working on festival attendee Dick Vollbrecht.

"I'm looking to get into a hybrid, so I thought this is the place to come," said Vollbrecht.

But for potential buyers like Vollbrecht, there are more green vehicle options than ever before, including after-market add-ons. For example, Smart Motors in Madison can convert a standard Toyota Prius into a plug-in hybrid, which can double the Prius' already high gas mileage.

Ricardo Bazzarella, of A123 Systems, one of the world's leading suppliers of high-power lithium ion batteries, said converting a car can also save money.

"We add a five-kilowatt lithium-ion battery pack to the back of a Prius. We actually don't remove anything out of the Prius. We leave the nickel-metal hydride in the car. What that does is actually doubles the fuel economy," he said.

Despite greater acceptance, hybrids are still fighting the stereotype of being small, slow, and not always practical. However, the perception of hybrids is constantly improving, aided by the fact that luxury cars, SUVs and even trucks are available as hybrid models. At Hybridfest, Ford is showcasing its Fusion hybrid, which the company says gets 41 miles to the gallon in the city.

"There's more that I'm learning from customers than they're learning from me, because at the end of the day, we want to design products that appeal to the customer. It's folks like people at Hybridfest that actually can tell us what they think the future should be," said Praveen Cherian, the Ford Fusion Hybrid project leader.

Vollbrecht agrees that hybrids are being taken more seriously by even people with casual interest in cars: "There's a lot of creature comforts in them now. They aren't the little box anymore."

Summing up the goal of Hybridfest, Powers said, "We really see it now as an opportunity to talk to people about hybrids and really tell them the truth so they can get the right information."

Organizers said there have been plenty of questions from fair attendees about hybrids, the most common of which is whether batteries need to be replaced. They tell them that batteries should last the life of the car.

Organizers also said they expect hybrid vehicles to become even more mainstream once gas prices rise again. Hybridfest continues on Sunday until 5 p.m.

For more information, go to the Hybridfest Web site.