The curious tale of the driver that did nothing
Several vendors are now shipping Qualcomm's Gobi chipset, a cunning dual CDMA-GSM wireless broadband device. There's a driver for it in the Linux kernel called qcserial which claims to support it.
Do not be fooled. This driver is a vile lie.
The hardware comes up in a dumb state and requires firmware to be loaded before it'll do anything. The only way to obtain this firmware is from a Windows driver. The only way to load this firmware is under Windows. This isn't helpful, especially given that it drops the firmware whenever you use rfkill or suspend or power down the machine. In fact, the only way you can use this driver is to boot Windows, let it load the firmware, reboot into Linux, get online and then never turn off or suspend your computer or the radio.
So, don't be like me - swearing viciously and trying to generate useful USB packet dumps in an attempt to get the hardware working. Known bad parts are the HP un2400 and the Dell wireless 5600 - sony also have a Gobi part that's used in the P-series machines, and Acer have one as well. I'll update this if I ever get anywhere with a firmware uploader, but until then remember that the presence of a driver in the kernel doesn't mean that you can actually do anything with the hardware. Fyalcomm.