http://www.freedompop.com/devices.htmYou put a deposit down on the device--$49 for the USB stick or $89 for the WiFi hotspot. You get the money back when you send the device back to them. Sleeve for iPod or iPhone 4 is $99. Not sure if that one counts as a deposit.
500 MB per month free; 10 MB per friend you refer, $0.02/MB overage.
They plan to make money off their paid plans: $17.99/mo for 2gb, or $28.99/mo for 4GB, both have $0.01/mb overage.
$2.99/mo removes the throttling.
Backhaul is of course Sprint/Clearwire--who else uses WiMax?