This would not be a convenient solution, (not designed for photography) but it should work. You could use a USB over IP host adapter, to allow USB communication over a Ethernet network. You could also use a WiFi bridge to connect it to a wireless network. You'd also need to convert each device to work with batteries, which shouldn't be too difficult as they natively take DC power. They might fit in your pockets, but a large vest or small backpack would be ideal. This set of devices would allow you to shoot over WiFi, and the E-3 and computer would both think they were plugged in directly. You have a theoretically unlimited range, relying on your wireless infrastructure. If they made one, battery powered, device that does this, it would be a lot simpler, but I'm not sure if they do.
Actually, you could use a netbook.
