I've also been collecting twitter data for a bit. I developed a heatmapping application that runs on the GPU to produce time-animated heatmaps in real-time for

I've also been collecting twitter data for a bit. I developed a heatmapping application that runs on the GPU to produce time-animated heatmaps in real-time for any user-generated query over a Solr database of hundreds of millions of geotagged tweets. You can see a rough demo at http://youtu.be/4_v2EZGiA7w http://youtu.be/4_v2EZGiA7w . Hopefully I'll release it as a web app when I get time this summer.