Of all the companies poised to benefit from the economic stimulus checks, Wal-Mart is expected to lead the pack.

Consumer research experts said a downturn in the economy matched with quickly escalating energy and commodity prices have pushed consumers and their checks into the arms of Wal-Mart (WMT), the largest discount retailer in the world.

“We are seeing consumers moving their purchasing habits toward necessities instead of looking to splurge their stimulus checks on a big item,” said Phillip Rist with BIGResearch. “That stands to benefit Wal-Mart and Target we believe.”

Wal-Mart plans to cater to the stimulus check crowd by offering free check cashing services for consumers’ rebates, clearly hoping to tap a portion of that money before it goes to credit cards or the gas tank.

Other retailers are taking it a step further: Sears and Kroeger will add 10% to the amount of a gift card purchased with a stimulus check.

Wal-Mart executives, meanwhile, are being cagey about the impact from the 146 million stimulus checks.

During the retail giant’s quarterly earnings call Tuesday, executives described the potential benefit of the checks as both “difficult to quantify” and “uncertain.”

The company also gave a conservative guidance for its same-store sales for the second quarter--the period economists expect those checks to be used. Wal-Mart predicted sales will be flat or up 2%. That’s below the consensus estimate by analysts.

"There are still uncertainties during the rest of the year," President and CEO Lee Scott told investors. "The economy is playing a critical factor in 2008."

One problem is that fewer people may spend those checks at Wal-Mart than originally anticipated.

According to BIGResearch, 7.6% of all consumers said they will spend their checks on gas this summer, that’s up from 5.3% when consumers were surveyed in February. Also, 47.1% of consumers said they will either use their stimulus checks to pay down bills or save it.

“I think Wal-Mart thinks that inflation and gas prices will eat away at those checks before they will really benefit from them,” said Joseph Beaulieu, a retail analyst with Morningstar.