Starting tomorrow, seven miles of streets in Manhattan will be closed to vehicular traffic between 7 a.m. and 1 p.m. for three Saturdays. In the place of cars and trucks, the city is letting people stroll or bike (there's bike sharing)--or take part in many organized activities, like tai-chi, salsa dancing and hopscotch. The program, Summer Streets, will be open from the Brooklyn Bridge to Central Park along Lafayette Street, 4th Avenue, Park Avenue and 72nd Street.

Mayor Bloomberg said yesterday, "We're going to embark on a grand experiment that could dramatically alter the way we use and look at the streets of New York. Streets that are normally tied up with cars and trucks will be turned over to the public - so that we can experience this city as never before. If the program works, we'll strongly consider doing it again; maybe we'll try it in other parts of the city. If it doesn't work, we won't, but we can't be afraid to find out." One concern is that businesses will suffer; supporters of the program urge people to frequent the establishments along the Summer Streets corridor.

If you're taking part, you can send us info at tips(at)gothamist(dot)com and you can share your Flickr photos by tagging them "gothamist." More information at the Department of Transportation and Transportation Alternatives, and for reference, Summer Streets was partly inspired by Bogota's Ciclovia, where 70 miles of the city are closed every week.