One of the most popular EVDO Rev 0 cards has been the Kyocera KP650. This has always been a Verizon Exclusive (AllTel has it, but Sprint never did).
As Novatel released Vista Drivers and support over the last month, it looked like Windows Vista users using the KPC650 were stuck, until the other day :)
Kyocera released a new firmware and Window Vista Drivers. Note that these are drivers ONLY. Verizon's VZAccess Manager is NOT Vista-ready for the KPC650.
See EVDOforums discussion below for the latest news and user reports.
Official Kyocera Vista Firmware & Drivers
Kyocera KPC650 Windows Vista Success/Failure
Vista and EVDO Cards - Compatibility Info