Cryoburn is already available on Audible! (I can never remember exactly when they update their catalog, or even if it's at a regular time.)

Just need to finish up 25 minutes of Quicksilver and then i can start in on Cryoburn for the second time :)

Oh, but just as a warning to everyone else who hasn't read it yet, stay away from related pages on Wikipedia until you're done with the book. There are some pretty major spoilers on there right now, some of which aren't even hidden away in the "plot" section like they ought to be =P