See Something Say Something (2011) by Eric Fischer

Eric Fischer creates maps using geotagged data from public sources. Here a map of San Francisco is formed by plotting the locations of Flickr pictures (red), Twitter tweets (blue), or both (white). What's interesting is that no underlying map outlines are used. The data itself is the map.

If you click through the link, you will see that readers have had fun highlighting areas they recognise, an example of leveraging a built-in Flickr feature to perform interactivity.

The title comes from the phrase promoted by the US Dept. of Homeland Security here.

"Cycling Through All The Streets In Central London" by Davis Vilums

Davis Vilums decided to take a different route to work each day, and tracked his journeys.

I am a passionate cyclist, and I love the streets of London. Most of my travels are daily 25-minute rides to work. Over time my route became boring. I decided to make it a little bit more interesting by taking the parallel streets on my way there. I bought a map of central London and started to colour in the streets to mark the routes that I have taken. And then I got obsessed with it.

The web page displays different visualisations, including an animation of the routes.

"The Interactive Movie Map: A Surrogate Travel System" (1981)

This documents work begun in 1977 with the interactive video Aspen Movie Map, which allows the participant to take a journey through Aspen, Colorado, based on pre-recorded video clips sourced from laserdisc. Developed by Andrew Lippman and team at MIT.