From AppleInsider:

The new iPhone 3.0 software will also add Bonjour discovery support, allowing iPhone users to discover nearby devices without requiring them to set up an ad hoc Wi-Fi network. Instead, the device will use Bluetooth to discover other phones advertising their presence, a feature that can be used in multiplayer games and other applications.

The feature is automatic and doesn't even require the presence of Wi-Fi; developers just need to call on the feature and build in a menu to show it off.

This is the biggest news of the iPhone's new OS. Now you've got all the tools to start making a mesh network, even on the iPod touch.

Seriously, this is huge. Get your workstation to speak Bluetooth to the touch, and you can start bucket brigade Internet access for pretty much anyone, anywhere. iPhones are always on, give or take, and now everyone with one can potentially be a relay point/Hotspot for everyone else in the world. That car in front of you has an iPhone? Get close enough (I'm not sure how good Bluetooth is at this, but you get the point), and, with the right app, your computer could send and retrieve email.

The best way around any future loss of net neutrality is to create a "People's Network," where we provide our own infrastructure. We're getting close with the iPhone now, though once the new unregulated, "WiFi++" deregulated spectrum comes "online", I think you'll see a lot more in the way of the mesh.