The world's largest retailer  is undertaking a sort of human genome project for sustainable products. With its new Sustainability Index , all 100,000 of its suppliers will be required to disclose everything from material efficiency to climate impact for each of its products, slap the data on its label, then compete for shelf space. Top 50: No. 9 
The App Store  continues its reign , with more than 140,000 apps and an estimated $1 billion in revenue. As does iTunes , which has made Apple the No. 1 music seller in the U.S. The introduction of the iPhone  to China, the acquisition of streaming service Lala , and the launch of the iPad  should push even more growth. Top 50: No. 2 
The iPad will no doubt take some of the shine from the Kindle  (within days of the launch , Amazon was backtracking on some its pricing ). But the company remains a powerful competitor with its new Kindle app store , deals that extend the reach of its MP3 store, and its one-click shopping iPhone app. Top 50: No. 2 
Take the brains of a Berkeley environmental and labor-policy professor and the ingenuity of Silicon Valley talent from Amazon, eBay, and Google, and you get GoodGuide , a Web site that pores through hundreds of pieces of health, environmental, and social data on products and the companies that manufacture them. So far, the startup, which recently received $3.7 million of VC funding, has rated more than 75,000 products-from food to toys-that can be easily accessed via a bar-code-scanning iPhone app. Top 50: No. 47 
Once a model of corporate autocracy, the sports giant  has embraced the open-source groove , opening itself up to collaboration with virtually everyone-from customers as shoe designers to sneakers as personal trainers to IP as a team sport. Top 50: No. 13 
6. Toms Shoes
After four years in business, 33-year-old Blake Mycoskie has proven that his socially conscious "one for one" model is more than just a novelty project. For every pair of his signature alpargatas sold, one free pair is given to a child in the developing world. Toms has expanded its line, won the 2007 People's Design Award at Cooper-Hewitt's National Design Awards, became a member of the Clinton Global Initiative , and landed shelf space in Whole Foods .
The Mexican food chain  not only keeps raising the bar for the food industry, its year-over-year revenue was up 13.8% to $387.6 million in 2009. Last year, it expanded its program that sources produce from a network of local farmers --the first of its kind for a national restaurant chain--and committed to installing solar panels on 75 of its stores.
8. Hot Topic
Culture is almost more important than cotton for this teen retailer , which has made the bold bet on music to boost clothing sales. Hosting free in-store acoustic shows, launching its own music social-networking site, and pulling off an exclusive licensing deal with cult fave Twilight, this public company has been one of the few retailers to buck the recession.
The Vancouver-based high-end yoga retailer continues to convert  the most popular yogis-along with their disciples-into devout patrons with virtually zero advertising. Demand outpaced supply even during the economic downturn, thanks to investments in better inventory-tracking systems and the expansion of its offerings for runners.
10. Best Buy
The Minneapolis-based electronics retailer  is taking on everyone from Hollywood to Detroit to Silicon Valley while its traditional rivals disintegrate. Its new partnership with CinemaNow means instant movies via its devices , while its launch of Best Buy Capital means incubating new technology companies.