The city is humanity's laboratory, where people flock to dream, create, build, and rebuild. In his book Triumph of the City, Harvard economist Edward Glaeser observes that to stroll through the world's great cities is "to study nothing less than human progress." Each year, we spotlight the building blocks of that progress -- bold ideas that promise to enrich our cities and economies. You'll find plenty in diverse, surprisingly creative Houston, our 2011 CITY OF THE YEAR  which urban theorist Joel Kotkin tips as "one of the world's next great cities." You'll also find these ideas across America:
Fast Cities 2011
O Pioneers! 
Reinvention, innovation, and cultivation make Houston our City of the Year for 2011.
The Evangelist 
Annise Parker, right, with her partner, Kathy Hubbard, was elected Houston's second female -- and first lesbian -- mayor in 2009.
SLIDESHOW: Houston, We Have Liftoff 
We asked 10 creative Houstonians to tell us where they seek ideas and boosts of inspiration in their hometown.
United States of Innovation 
CLICK THE FIRST LETTER OF THE STATE to browse 51 -- yes, we included the District of Columbia! -- bold ideas and brilliant urbanites who are helping to build the cities of America's future.