After filling in Microsoft's online form, I got an email advising me that there are three methods for returning consoles (electronic label, paper label, pre-paid shipping box) and that I would be assigned one of the methods. A little later my electronic UPS label arrived by email so I packaged up my console and checked out where the nearest UPS depot was (Eastleigh: 7.2 miles). After ensuring May had adequate supplies, I dashed out to the UPS depot on New Years Eve, arriving about 40 minutes before they shut for the day. After ringing the buzzer, the chap who came to the door took one look at my parcel, and opened the door saying "Welcome the the Xbox Hospital". A bit of quizzing revealed that my delivery was his 10th of the day for New Years Eve, and also that he gets an average of 40-50 a week. Pretty staggering given that I was using one of three shipping methods.
My console arrived back today, 16 days later, seemingly repaired but running in hilarious 640x480 resolution. I was all ready to phone Microsoft and complain about the fact I'd been paying for Live while my console was away but not able to use it, but I have to confess I was quietly impressed to discover they'd pre-empted me by putting a 30 day Live card in the box with the return.