We do love those nanotubes, at least if the volume of posts on WorldChanging about their sundry capabilities is anything to go by. If you love those nanotubes, too, you need to put the Nanotube Site on your list. Operating by David Tomanek at Michigan State University, the Nanotube Site is intended to: ...facilitate the exchange of ideas among researchers by concentrating links to sites dedicated to nanotubes. One of the benefits is to provide an easier (or better structured) electronic access to bibliographical information and preprints. Information about providers of nanotubes is intended to increase the production volume and find new applications for nanotubes.
Not solely focused on nanotubes, Nanotechnology Now - http://www.nanotech-now.com/ - covers a lot of ground that includes much of what Tomanek has. Also if you're looking for links, the Open Directory Project should cover them (and if they don't have all the ones Tomanek lists, somebody should submit them!):