You won't find many city employees more jazzed about their jobs or more committed to the mission than Laura Spanjian, Mayor Annise Parker's director of sustainability. When she recently entertained 10 counterparts from cities across the country, she took them to dinner on two-wheelers from the city's Bike Share program (her baby). And rather than the expected Tex-Mex or barbecue feast, they cycled to The Pass & Provisions.

Since arriving in Houston in 2010 from her native San Francisco, Spanjian has tackled the meaty issues of municipal energy efficiency, renewable energy, recycling, alternative transportation and improving air, land and water quality. On a more tangible level, she instituted the popular City Hall Farmers Market.

Her efforts combined with those of various city departments have placed Houston for the third consecutive year as the top municipal purchaser of green power. Today, the city boasts 20 LEED certified projects with eight more in the pipeline. Six million square feet of city buildings have been retrofitted to reach a 30 percent energy reduction. The city has 40 electric and hybrid plug-in fleet vehicles with more on the way. All of this a hefty charge for even the most enthusiastic environmentalist.

Two of Spanjian's biggest initiatives at the moment are increasing the number of bicycles and the areas served by Bike Share and the ambitious One Bin For All program.