A few weeks ago I had the honor of giving a talk at the first OpenVis Conf in Boston, organized by the fantastic people from Bocoup. The conference's goal was to talk about visualization on the web and how to move that field forward. In the two days there was an amazing density of content, brilliance and enthusiasm and it really was the place to be for anyone interested in vis on the web.
My talk - 'Data on Your Fingertips' - was a primer on touch-centric interaction design, as there are only few examples of touchable visualizations out there (yet). Regarding the web, I unfortunately had rather dire news - most tablets and smartphones are simply too slow to do interesting web-based visualization in real-time (don't worry - pie charts are possible). But we're getting there and I have high hopes for developments such as WebGL.
And I also highly recommend to check out the rest of the talks.