Almost works out of the box on Ubuntu. Will work out of the box in the forthcoming 9.04 release.
One curious little detail: according to the manual, a blinking green light means it's trying to find the GSM network (if it's blinking twice every 2.7 seconds) or that it's successfully found a GSM network (if it's blinking twice every 2.9 seconds). I'd like to have been on the meeting when this was decided. "I know! Let's make it blink 0.2 seconds faster to indicate it hasn't found a network yet! Brilliant!"
Update: given its shape and position next to my right-hand USB ports, it should double as a USB mouse.
On an unrelated note, Sweden is a very nice country.