Plug: Google Fusion Tables
By mattwigway
Google Fusion Tables is a fairly new service many may not have heard of: it lets you manage large tabular datasets in the cloud, using Google’s infrastructure. You can then visualize that data in a variety of ways, including a Google Map. The coolest feature in my mind is the ability to geocode addresses to a map on the fly. There are lots of datasets out there that, rather than providing a mappable latitude and longitude, provide an address column (or street, city, state, &c., which is easily turned into an address column using the concatenate function of your favorite spreadsheet)–many of the datasets on DataSF are like this, as are many others.
Here’s Google Research’s official announcement: http://googleresearch.blogspot.com/2009/06/google-fusion-tables.html
And the product itself: http://www.google.com/fusiontables/Home