The spring NEARC fleamarket/swap meet is this Saturday 19 April in lovely Manchester, NH (or Manch Vegas as it is inexplicably known to some).
www.nearc.net

The annual MIT flemarkets kick off this Sunday 20 April in even lovelier Cambridge, MA (much more explicably known to most as the People's Republic of Cambridge).
http://web.mit.edu/w1mx/www/swapfest.html

You have been warned.