I found this on Kottke.org, and decided to bring you the link from there because it gives more explanation than if I linked you to an awesome photograph of All of The Rivers.
Nelson Minar may have been inspired by the All Streets  project when he created this awesome map using all the rivers in the United States. If you click the link “built a US map out of all the rivers in the country” you’re whisked away to the Flickr image which is much larger and in my opinion more impressive.
If you scroll past the images, you’ll see a link “up on Github ” which will take you to Minar’s project on GitHub. It is a tutorial on how you can do this project yourself and provides all the open source data you need to complete the map. It explains the different steps and the different sorts of programs you need to complete the map, as well as suggestions for other projects along this theme.
Go check it out!