For those driving to the conference, we've been able to negotiate special parking rates with a local aggregator. Here's their pitch:
"Just for the attendees of Djangocon, we would love to offer $20 toward parking for anyone who tries out our service. Our company SpotHero works with the garage a block away (and many others) to offer discounted parking options. Just download the SpotHero app on iPhone or Android and enter the promo code: djcon13. You can also get a spot on the web by visiting the DjangoCon Parking Page."
A couple of notes:
you'll need to register yourself on SpotHero's web site to access the promotional rate;
most parking facilities do not allow in/out privileges (a couple that do are about a mile from the venue). Apparently a car leaving a garage is a taxable event in Chicago.