Nice job - congrats. Is it difficult to prevent gaming the results? I'm curious about "pump and dump" approaches that exploit the social media data stream.

It's an interesting question and we haven't had any problems so far. The good thing is that our data feeds are vast in terms of both size and reach across the social web, and we don't overly rely on any one feed.

What is your technology stack? I am particularly interested in the graphing library.

Just hackin' away with PHP, jquery, and MySQL ^^ The graphing libraries can be found here http://www.highcharts.com/ They've been uber easy to integrate

What's your infrastructure like? I imagine this would require lots of hardware for all the crawling and analysis?

A couple of local Linux boxes we have set up so far, and will be utilizing Rackspace cloud more in the near future.

haha.. Things are starting to get a little crazy in that area, but for now we are getting away with a few synced up designated data crunchers (crawling and crunching in C++ goes a long way as well!)