You'll find your 12 digit code on specially marked 330ml cans, 500ml and 2l bottles of 'Coke', 'Diet Coke' and 'Coke Zero'. On can multipacks it is printed on the inside of the cardboard pack.
Gimme some skin! These funky adhesive skins stick on, peel off - and most importantly - don't leave a horrible sticky mess behind. Slap one on and hey presto! Your iPod will look as good as it sounds.