Earth's 911 - A comprehensive website with information about recycling programs organized by zip code.
Freecycle - Online bulletin boards, organized by city, where you can give away your old stuff to keep it out of a landfill.
The Internet Consumer Recycling Guide - A starting point for consumers searching the net for recycling information.
New York City Recycles - Lots of information about what and how to recycle in New York City from the Department of Sanitation.
Recycler's World - A world wide trading site for information related to recyclable materials.