I was interested to see recently that Google had opened up their data visualization infrastructure. One part of it is a tool that anyone can use to visualize publicly available data — the Public Data Explorer.
[Clip]
They have a directory of many public datasets, but you can also upload your own data and use their tools to visualize it.
See Also: Many Eyes from IBM (Another Free Tool to Visualize Data)
Users have an option to upload their own data sets.