Internet cellphone "boosting"

I live in an area of universally poor cellphone reception. Every day, I see people walking around outside their nearby homes, hoping to wander into an elusive hotspot that can best sustain their connection. I am an AT&T customer using just an old, Nokia "dumb" phone, and previously, I had been able to use an AT&T AirCard here, though, because I am a low power user (basically e-mail and news articles only), I can't say whether my 3G AirCard service was performing optimally

Recently, someone moved into the neighborhood and he found his Sprint reception here to be unacceptable. He is a more "high power" user, with a tablet-like phone (when they say after my flight lands, "You may now turn on your electronic devices", I'm one of the few who is still slumming it: nearly everyone else is poking an LCD screen nowadays), and he kept talking about how few "bars" he was getting here, saying it impeded his ability to get his device to do some of the things he wanted it to do.

He remedied his own Sprint signal power/quality problem by obtaining from them, at no charge, something that he plugged into his Verizon wireless router that enabled that internet connection to broadcast his needed cellphone service. I hooked it up for him, and I assisted him in authorizing or activating it, and as I recall, we didn't even have to incorporate his WEP key into the authorization, but it didn't work for him until this authorization or activation had been completed.

Is there something similar available to me, an AT&T "dumbphone" user, either for free or for a hardware or subscription charge? I am surely beyond my contractual commitment, so I have the negotiating leverage of renewing/extending or changing providers. If getting internet cellphone transmission would require that I upgrade to a more expensive data tier of service, I could consider it, but that is not of much value to me at present, as I get free Verizon internet via "cable" here paid for by my landlord, and if it is possible for the Verizon internet to be used carry my cell broadcast signal, could I simply "piggyback" off his nearby Sprint interfacing unit or would the needed interface device also be proprietary to my provider and possibly unique to me as a customer?