Walmart.com’s mobile commerce site was the only mobile shopping site among numerous evaluated to receive a passing grade, 70 or higher, from Yankee Group Research Inc. Best Buy Co. and Amazon.com Inc. nearly tied for second place.

“Walmart doesn’t score a passing grade of 75 because it is the most sophisticated site, but rather because it is the site most focused on delivering value to the mobile user,” write analysts Carl Howe and Tole Hart in the report, “Best of the Anywhere Web 2010.” “Walmart restricts its mobile web site to only six main menu items, but still manages to use mobile context by exploiting location information from iPhones and BlackBerry Torches to locate nearby Walmart stores. Walmart is further the fastest responding site in the shopping category as measured by Keynote Systems, and it boasted 100% uptime during our test period.”

Best Buy earned a 68 out of 100 and Amazon.com a 67. Yankee Group cites Best Buy’s incorporation of location detection to find nearby stores as one key feature. “Amazon.com provides a broader shopping experience, but proves overly enthusiastic,” the analysts write. “It pushes larger pages at users, and it fails to take advantage of the features of mobile devices.”

Target Corp., with a score of 64, and Cars.com, 63, round out the top five shopping sites. Yankee Group says their failing is not applying appropriate device adaptation. “Target doesn’t provide location detection for advanced browsers such as those on iPhones or Android devices,” the analysts write. “Cars.com, on the other hand, requires users to choose the type of site they want to visit. Because users rarely know which type of site is most appropriate to their phone, this approach fails to achieve the types of scores that best-in-class Walmart, Best Buy and Amazon achieve.”

Yankee Group’s Mobile Web Report Card comprises 25 questions that evaluate a mobile web site among five broad criteria: how much a site focuses on the “anywhere user,” as well as how easy it is for users to achieve specific mobile goals; how well a site adapts to the devices mobile users are carrying; how well a site’s content is designed to work on carrier networks; how well a site design contributes to mobile usability; and technical and usability issues that Yankee Group believes are important to a good “anywhere experience.”

Each question is rated with one of four grades: critical omission, where a site makes no attempt to address the criteria specified by the question; needs improvement, where a site attempts to address the question, but fails in its attempt; pass, where a site successfully satisfies the question; and high pass, where a site satisfies the question in a particularly memorable or elegant way. Each of the 25 questions can contribute up to four points to a total assessment grade of 100 points.