Clear has mobile internet, with or with out a contract - at the same price, does not make much sense, because what would the motivation to sign a contract with the potential for an early termination fee if you did not have to.
Any how, Clear is offering 2 versions of their mobile WiFi unit. The Spot, and The iSpot. Both devices sell for $100. The different versions both offer unlimited internet connection for several devices, however one device costs $45 per month, while the other costs $25 per month.
The $25 per month price is for the iSpot, which is for "iDevices" only (meaning that they only support apple devices such as iPod, iPad, etc. It is not designed to connect with a laptop, or other non-apple products. A quick internet search shows that the device is using MAC filtering to prevent non-apple products from using this service. With Google you can figure out how to spoof your MAC address and use an iSpot with your laptop (or other non-apple product)
Or you can always just opt to pay the $45, it is only $5 more per month than Virgin Mobiles mobile internet.