It's a work around, not a solution. A lot of people have a lot invested in their iOS devices (device plus apps) this is a way to switch to TING and maintain most of your investment until TING gets an iPhone/iPad.
I bought a refurbished LG Optimus S from TING, the cheapest phone with mobile hotspot.
I ported my iPhone number to Google Voice (excellent tutorials on setting up GV Using Google Voice on your Ting phone : Ting Help & Support http://ow.ly/mvfZ3 ) and had a new number issued to the TING phone. I routed my GV number (old iPhone number) to my TING phone.
I turned off my AT&T service to the iPhone and iPad. Essentially I turned my iPhone into an iTouch. Installed Google voice on all of my devices.
I don't make or receive many voice calls, so it's not too much of a pain to have the LG for voice calls.
When I'm around work or the house, the iDevices connect on my local wifi routers. When I'm in the car, I turn the LG TING hotspot on and my iDevices connect via the TING account. As long as I remember to turn off the hotspot when I get to work or at home, forcing my iDevices to switch back to the wifi networks, I don't run up much of a TING bill usually.
Because I'm using GV for my telephone number, the TING LG stays plugged-in out in the car most of the time. If my GV rings, I'll catch it on the computer or Skype back.
Since my AT&T voice/data/messaging bill was between $150-175 dollars per month PLUS the AT&T data plan for the iPad ($25/month), I'm saving BIG with not too much trouble to myself.
Like I say, it's a workaround, not a solution, but to save $1200 a year, I'll deal with it. If the iPhone ever gives up the ghost and if TING doesn't get an iPhone, I might switch to a highend Android device. But this is the most cost effect use of my investment I could come up with.