small teardrop/ Thermometer icon

Like everyone here; I am an old Palm user.
Palm III through TX now. I use a BB phone, 8320.
Wi-fi is the future of handhelds. My technolust is craving a Nexus.
Question: I have a small teardrop/ Thermometer icon in lower right corner of the screen on one of my T3s and now on My TX since I started using the wireless keyboard.
Also in the past I paired my T3 with a Moto L2 phone and a Moto V51 for a great browser. Now I have a BB8320 and would like to network to AT&T via the large screen of my TX. I use a a pay as you go plan like Hook referred to.
Like everyone here; I have customized my palms heavily. If my Treo 650 had not died. Would still be using it.

Still love my Palms since 1999.
Thanks in advance.
Guy