Last night I installed Layar on my phone, and had some fun checking out the twitter and wikipedia layers. So I signed up for an API key, and 30 seconds later saw a tweet mentioning the California Data Camp. Perfect! After a rare and blissful sleep-in, I wandered over to see what was going on at Citizen Space, thinking I'd try get a proof of concept demo showing some City of SF data in Layar.
Turns out, despite a number of interesting conversations taking precedence over my coding, I managed to get a simple demo working, and even win Honorary Mention (and an iPod touch) for my efforts. And a couple of Layars (crime data and handicapped parking spaces) are just waiting for publishing approval from Layar, and will hopefully be available in a few hours. Just search for "datasf" in your Layar app.
Since GeoDjango was the reason I was able to get a mockup going so quickly, I thought I'd just write a few short notes on the steps I took to build the Layar compatible API, and make the code available. Note that the code here is not particularly pretty - it's the result of a partial afernoon of work (including finding/downloading the layers, going over the layar api docs, and dealing with incredibly spotty internet connectivity). Nonetheless it may be interesting to some geodjango newbies as an example of a quick proof of concept.
[EDIT]: I now see that someone else (sunlight foundation) had already built a more robust generic view for django, called django-layar. You should definitely use theirs instead .. but if you're curious for more ways to load spatial data into geodjango you might find my notes on google code interesting anyway.