FreedomPop, a year-old startup backed by Skype founder Niklas Zennstrom, has officially flipped the switch on its much-anticipated wireless data service that will give 500MB of free 4G wireless data each month to anyone willing to fork over a deposit for one of its modems. The company currently runs on Clearwire's 4G WiMAX network but will switch to Sprint's 4G LTE network early next year.

FreedomPop offers two different modems for users to get online: the Freedom Spot Photon, a portable hotspot that supports up to eight simultaneous devices, and the Freedom Stick Bolt which is a USB modem that allows for a plug-and-play connection on your laptop or PC. Both devices are technically free though customers have to put down a $89 or $49 security deposit for the Photon or Bolt, respectively. The company will also begin selling sleeve modems that fit over the iPod Touch and iPhone 4 and 4S in four to six weeks.

As mentioned above, everyone gets 500MB of free data allowance per month, with no long-term contracts or ads. Beyond that users can either earn extra bandwidth by referring friends to the service, up to 1GB per month in 10MB increments per referral, or switch to one of the company's prepaid plans. The latter are priced 20% to 40% below the rates of many major carriers, says FeedomPop, at $10 a month for 1GB, $18 for 2GB, $29 for 4GB, $35 for 5GB and $60 for 10GB. Customers on these plans pay $0.01 for each MB of overage.

The company is testing several value-added features as a way to boost revenues without recurring to unwanted ads. One of them involves a $3 fee for a "Speed Plus" service on top of the free plan to guarantee no throttling when the network is congested and prioritizing packets over those of non-paying customers. Another possibility is the option to allow voice calls over the network for a fee, although this hasn't been confirmed yet.

The beta is open to anyone in the US with Clearwire WiMAX coverage, which currently equates to roughly one-third of the country. The company isn't restricting customers to a single device, which means two or more users in the same household could get their own hotspot with a separate 500MB monthly allotment.

FreedomPop is not the only company offering free broadband in the US. Back in March, NetZero, which made a name for itself in the late '90s for giving away free dial-up Internet service, also launched a free broadband plan on Clearwire's WiMAX network that limits users to 200MB of data per month – with paid options available.