NEW YORK (CNN/Money) - It's already the king of retailing. Give it another five years or so and Wal-Mart may be on its way to conquering other valuable little nuggets of the business world.

For instance, why shouldn't the world's largest retailer open its own Wal-Mart banks? The opportunity is clearly there given that 20 percent of Wal-Mart shoppers currently don't have their own bank accounts, according to market research firm Retail Forward.

"Wal-Mart is already testing the waters," Sandy Skrovan, Retail Forward's vice president and retail analyst, said in an audio forum Wednesday titled "Wal-Mart: How Big? How Far? How Fast?"

The forum, which featured a panel of analysts with the firm, was monitored in New York via telephone.

Said Skrovan, "Wal-Mart last fall in its conference call with analysts listed financial services as a key growth initiative for the company. Obviously there may be some legal hurdles with this, but the possibility is there."

Despite its wobbly performance during the 2004 holiday shopping season, when consumers shunned Wal-Mart for being stingy with discounts, Retail Forward projects that the company is still on track to hit $500 billion in sales by 2010, accounting for a whopping 12 percent of all retail sales in the United States.

"While the world waits for Wal-Mart to collapse under its own weight, Wal-Mart waits for no one, demonstrating a remarkable capacity to manage the retail life cycle and keep right on rolling," Retail Forward said in a recently published report Wal-Mart 2010. The firm provides market and consumer research to Wal-Mart.

But while Skrovan said consumers should expect Wal-Mart to become an even bigger force in areas such as food, beauty, clothes, toys and electronics, watch out for Wal-Mart's footprint to expand outside of retailing.

Aside from banking, she lists travel services, healthcare, fuel refining and publishing as a few of the most appealing new businesses for the retailer although some industry watchers say they're skeptical about those growth areas.

"Wal-Mart already offers travel packages to consumers. It's testing car rental service in a few stores. In 2010, maybe consumers could even fly the friendly skies with Wal-Mart," Skrovan said.

Wal-Mart is already the fourth largest pharmacy in the country. It's not implausible that Wal-Mart would offer in-store eye checks for prescription eyewear and contact lenses, or even dental care.

Added Skrovan: "Wal-Mart already has gas stations at a few of its stores. Maybe it could move upscale into oil refinery." She also sees publishing as a logical new business venture for Wal-Mart.

"From here, we expect Wal-Mart will continue to push the boundaries to meet any consumer need," she said.

Wal-Mart spokeswoman Sharon Webber said the company already offers eye care in Wal-Mart supercenters. "That's where I get my glasses," Webber said.

"As far as banking is concerned, we do lease space in about 900 of our supercenter stores to regional banks. They are not Wal-Mart operated. It's more of a landlord-tenant relationship," she said.

Regarding Wal-Mart's possible foray into publishing or fuel refining, Webber declined to comment, other than saying that Wal-Mart is "always looking for better ways to serve its customers."

Skrovan's ideas sound far-fetched to George Whalin, an independent retail analyst.

"These little niche markets such as banking and publishing don't make economic sense for Wal-Mart," Whalin said. "Wal-Mart will never dominate in banking because of regulatory issues.

And while selling gas may be a nice adjunct business, people will keep buying gas at gas stations closer to their homes, he said. Publishing's also a long shot.

"It's a highly volatile business and simply not Wal-Mart's specialty," said Whalin. "Let's not forget that Sears tried getting into a lot of other businesses -- it was selling insurance, it had a car rental service, a credit card business. It turned out to be a disaster."

"These are not cookie-cutter businesses. They require unique discipline and mind set," Whalin said.

Wal-Mart's real growth in the next five to 10 years will come from international markets, Whalin said. "The no. 1 domestic growth driver will be grocery. Wal-Mart has a lot of room to grow there. It's already the No. 1 grocer in Texas."

Retail Forward analysts didn't dispute that fact, saying they expect sales in other countries to account for a third of Wal-Mart's sales by 2010.