Cory Booker, the Mayor of Newark, New Jersey, has a sore back. He's spent the past two days using Twitter to connect with residents of his city that were trapped by the recent snowstorm. After he finds the ones that are in serious need of help, he goes over and digs them out himself. He's also used the service to turn his constituents into a team of informants spread across the city, finding the streets that are in dire need of a plow.
If the mayor of your own city is less accessible, there are other options for finding help using social media.
Ushahidi, a crowdmapping tool that was developed to track elections in Kenya and was used to coordinate emergency aid operations in Haiti after the devastating earthquake, has been incorporated into two helpful sites focused around Boston and New York City. Built by PicNet and Non-Profit Soapbox, two development companies that build websites for non-profits, the Snowmageddon Clean Up sites offer a simple way for individuals to seek or offer help around a number of different categories that range from "snowblower available" to "plows needed." The site allows users seeking help to include time, location, and a description of the problems they face.