For one, we're using them to act as SMS gateways to generate activation codes. Essentially they receive confirmation messages for mobile payments to a particular number and we wrote an Android app that generates a unique activation code and sends it back to the payer. Better than a PC because it's cheap, has redundant power, redundant network and better connectivity with the GSM world.
The other task we're using them for is to act as network attached barcode scanners for inventory control. Essentially using the camera to read QR codes and allowing people to move / receive / send inventory using a rich app interfacing to the cloud based backend we are building. They are amazing for that.
I guess my point is that this isn't just a milestone for the consumer, it is a milestone to have an easily programmable, portable, GSM connected device with a camera and a touchscreen that only costs $80. Nothing else compares.