A website that takes data from the masses on whether they are long/short a particular stock to formulate an aggregate opinion on where the stock is headed. I know people are data mining all the tweets on twitter to do this but I'm wondering if there is some website that posts this kind of data. Any ideas, thoughts?
Exists. I think Etrade does it as do some of the deep deep discount brokers. Question is how will this data be useful. I think the Twitter fund is doing well, but how I don't know.
Boardcentral is a good way to visualize "public" interest in a particular stock. Note that by the time that bored central has it as a "popular discussion" that the "public" has already seen the news or whatever made the stock move. So your already late to the party by the time you see it on board central. If anything the site should be used to see what to fade. Boardcentral is an interesting site nonetheless . I think google has stated that they tried to collectivly predict the market from "trending" topics on google search. Didn't work for them. Price/volume will reflect any insiders or large buying/selling before any "trending" searches will.
Motley Fool has a caps rating that sort of mimics your idea. The question is whether you would use it straight or as a contrary indicator. Have you ever looked at the AAII survey? http://www.aaii.com/sentimentsurvey This survey is read as a contrary indicator but in fact, it is right until the end of the trend, then it is wrong.