Lacoste is letting fashion-savvy consumers browse and buy the season’s latest looks via a new mobile-optimized site.

M-commerce technology provider Usablenet Inc. is the power behind the throne of the top performers on this week’s Keynote Mobile Commerce Performance Index. Four of the top five retailers on the index—Dell Inc., Walgreen Co., CVS Caremark Corp. and Victoria’s Secret Direct—are Usablenet clients.

The Massachusetts Bay Transit Authority has rolled out a new mobile-optimized site to let consumers stay on top of transportation information.

New figures released by mobile platform firm Usablenet underscore the need for retailers to have mobile-optimized websites.

As consumer adoption of smartphones continues its meteoric rise, organizations are now confronted with the challenge of developing a comprehensive mobile strategy that reaches a new generation of global consumers who are increasingly using the mobile Web as a primary gateway to the Internet.