StockTickr says it’s “social investing” and “it’s the easiest way to store a watchlist on the web. Uncover new trade ideas, use RSS to track stocks, and more.” I admit I don’t know jack about stocks so I can’t give a good description of what this does, but it does say it’s social, and it has tagging and RSS feeds, so that’s good enough for me. They need someone to make proper Web 2.0 logo for them though.