For instance, I made my own map of San Francisco with an events search from Zvents (salsa dancing Monday at the Jewish Community Center, for example); Google Real Estate Search (there's a one-bedroom, one-bath apartment in San Francisco's Mission District selling for a mere $389,500); temperatures from WeatherBug (62 degrees in downtown San Francisco); prices at gas stations near my office from GasBuddy ($3.79 a gallon at the Shell on Bryant and 4th Street); and running routes from MapMyRun. But right now, nothing to help me map my bike route to work.
Users can browse the 100 or so maplets for content to add to their maps. There aren't necessarily a lot of maplets available right now, but I'm sure the list will grow. For instance, searching for "bike" there was only bike path maplets for Boulder, Colo., and New York City. But residents of Tokyo and Santiago, Chile, will benefit from having access to their subway maps available.