FreedomPop offers its refurbished FreedomPop Freedom Hub Burst 802.11n Wireless 4G Router bundled with a 10GB 4G/3G Data Plan 1-Month Trial for $39 with free shipping. That's $11 under our mention of a refurb from last fall (which lacked a 1-month trial) and $60 under the price of a new one alone. It features WEP, WPA, and WPA2 encryption. The trial subscription begins once you activate the service. Be sure to cancel your subscription before the end of the trial period, or you'll be charged $18.99 every month thereafter for 10GB of bandwidth.
Note: No warranty information is provided.