Now what would be nice is if someone would start a service, say a mobile-web-first service, that a bunch of independent cab drivers could sign up for. Then that service would act as a dispatcher (taking a cut of the fare), and send a dispatch message to whichever independent cab driver is closest by. Of course that sounds a lot like what Uber is doing. Which then goes back to, are these drivers independent, or are they working for that dispatch service?
To make it truly independent, they would need to have more than one dispatch service that they could work at the same time (say both Uber and Lyft). And have a protocol so that dispatches from both services don't step on each other. Plus the ability for a customer to flag them down at random. Now they really are a self-employed contractor using these services as customer discovery / dispatch services.
Plenty of old fashioned taxi companies that operate via a phone number or text messages. You don't need Uber if you want to be a freelancer. And as a court ruled, you're not actually a freelancer if you work for Uber.