One popular demonstration from VisWeek was the ‘Choosel’ webapp which allows you to import and visualization CSV data via a highly interactive webapp.  No software install is required, and a wide variety of datasets are available.  Just paste in any CSV dataset and then use the interactive tools to annotate, visualization, and explore your data.

Choosel – Teaser CASCON 2010 / VisWeek 2010 from Lars Grammel on Vimeo.

Choosel.