It's an iOS app, because that's what I do. Even better, it's a script in the WhirlyViz app.
My entry to the competition is the app. More specifically, it's the Bay Area Bike Share Stats visualization within WhirlyViz.
First, go install WhirlyViz. It's fine, I can wait.
Next, find the "Bay Area Bike Share Stats" entry.
There's instructions in the upper left. But just go ahead and tap on things. No one reads the instructions.
Don't have an iPad or iPhone? It's cool, I won't tell anyone. You can just watch the video.
The back end technology is PostgreSQL running on an Amazon ec2 instance with a simple node.js front end. This is the first time I've bothered to stand up something like that and it was interesting. It makes me appreciate the commercial services and what they do.
It turns out several cities use the same format for their bike availability feed. Look for the "City BikeShares" entry in WhirlyViz.