Carrier Compatibility
Compiling a list of networks compatible with the Pyra modem.
US
Look for a GSM network, like Tmobile or AT&T. (Verizon and Sprint use CDMA networks, which are incompatible with the Pyra modem.)
There are smaller companies which use the Tmobile and AT&T networks (i.e. Virtual operators such as Cricket Wireless), but you'll have to look through for the GSM carriers with a BYOD policy.
Australia
Australia requires the European Pyra Modem. See this Whirlpool Forum post for more details.
Europe
Pretty much everybody???