social bookmarking portal lets users share expertise on some subject; room for author's comments and explanations; more discursive than delicious; less writing than a blog; see "Visual Thinking," also "Ephemeral Films"
Firefox extension offers an addictive way to search via categories or keywords or happenstance; you train it, with thumbs up or down on sites, so it learns your tastes; I prefer searches on keywords so far, and have had little desire to "network"