Ning appears to be a very cool Web 2.0 app that lets anybody create a "community of interest" around their chosen topic, inviting anyone to share and share alike. Ning lets you create web apps for specific topic areas, into which other users can pour their own bookmarks, ideas, and thoughts. They've provided a number of categories to get us going: Bookshelf, Wishlist, Photo sharing, Trail Reviews, Restaurant Reviews, etc. And then enterprising customers have created Nings of their own with topics like cute dogs, developers-for-hire, sweets, stupid things, etc. Think I'll sign up and give it a whirl! Just a thought, though... once anybody can create a "Del.icio.us" of their own, won't there be too many to choose from? 
P.S. It looks like Ning's Ajax and DHTML chops are provided by Dojo.
