Anyone used Freedompop with their iOS device yet?

Freedompop has been around for a little while, but I haven't really heard of them until recently. They have a case for the iPhone 4/S and iPod touch 4th generation that once purchased give you free wifi monthly.

Sure, you only get 500MB a month, but with how tight some of these data plans are anymore, that extra could be a huge help while on the go.

Anyone use the service, or thought about trying it out?