A colleague pointed me at this post, as we are working together on a project related to open data sources: http://readwrite.com/2008/04/09/where_to_find_open_data_on_the#awesm=~oARWkzqt2h9Anp
Many of the data sources I had already heard/known about, but a few new ones which I hadn’t. For our project, we have been looking at the OpenNYC data sets, which has some really interesting data domains contained within it. Hopefully we can publish our analysis of the open data sets and the obstacles for integration in the near future.
(Yet another data source list here: http://blog.visual.ly/data-sources/)