River map of the entire US

I came across this interactive map of the entire US river system. As you zoom in, you see more detail with the size of the line indicating the amount of flow from that source.

http://www.somebits.com/rivers/river...37.874/-97.044

Enjoy.

Edit: for some reason, I get a tiny map in Firefox but a full screen map in Chrome.

Someone (I think it was Slate, but I'm not sure now) reported on another version of this kind of map:
http://nationalatlas.gov/streamer/Streamer/welcome.html

I ran across yours trying to find this one. I thought they were both pretty cool, but I have to admit I prefered this one.