Here's a simple site I threw together to collect photos from Coachella via InstaGram. It's using InstaGram's Real-time API to receive notifications when users upload new photos from Coachella, Python via Flask on the Server and a combination of dojo and 320 and up on the client.
The GeoRSS feed from USGS makes doing simple apps showing recent earthquakes pretty simple. Here's one I did a year or so ago: http://swingley.appspot.com/maps/eq