My dorm has great Wifi but almost zero AT&T cell phone signal, because it is essentially a huge Faraday cage. However, I am often in places with no Wifi but great AT&T service. Is there some scheme by which I can give out just one phone number, and have it ring my iPhone via either AT&T or Skype/Wifi depending on availability? My ideas so far: 1. Buy a cellular telephone signal relay and booster, and install it in the dorm. Con: Expensive, may not work, a hassle. Which one should I buy? Suggestions welcomed and wanted, reply below. 2. Do something with Google Voice. How does this work? I would need to do research. 3. Use some other service that I am not yet aware of. Suggestions? If this service exists, it isn't advertising well enough. I will give someone a few bucks a month for this number forwarding service. But the plot thickens: A. I don't have exactly zero signal in the dorm, so the phone rings about 50% of the time if I am in the dorm. Once I pick up, the call usually disconnects unceremoniously after an average of three seconds. The ideal solution would try Skype automatically every time I am in the dorm, even though the phone might ring and work for a few seconds using AT&T. B. I don't always want to use Skype whenever Wifi is available, because I can't walk and talk if I do that. You can't walk from one Wifi hotspot to another while using Wifi smoothly, and you certainly can't walk away from a Wifi hotspot and into the wilderness. I really need "Hotspot at Home", but that is a T-mobile thing. Also, would I even be able to make it work with my dorm's Wifi access points, because I can't tinker with them? Thank you.