Free Online Chart Books from NOAA

Anyone who sails on the Chesapeake bay needs to know about this: NOAA is making booklet charts of the Chesapeake available for free download, as a test of the service (Thanks to Chesapeake Bay Magazine for alerting me to this). The NOAA Office of the Coast Survey website has a lot of great stuff available, like online editions of the US Coast Pilot guides (made for primarily for commercial shipping, but interesting reading on topics ranging from identifying whale species to the proper nomenclature and protocol for reporting of icebergs) and access to the historical maps and charts collection.
They used to also have an online chart browser that would let you select and download high resolution images of historical maps, modern charts, and coastal aerial photographs. Unfortunately, they now apparently want you to pay for them. It's too bad - they make great desktop pictures.