There’s now a growing database of Leica’s lens codes for use on the M8. Why pay $120 and wait 6–8 weeks to have Leica code your lenses when you can do it yourself with a marker?
Check out this how-to by Mike Prevette on the Leica user forums for details.
Previous posts on the subject: Hacking Leica digital lens coding, Leica M lenses coding for digital, Free digital coding upgrade on new Leica lenses in US & CA
Via the ever-vigilant Auspicious Dragon Photostream