I have used cold packs (aka "ice packs") on the clavicle area to good effect. 15 mins on, 15 mins off and 15 mins on. This was for symptoms in that area. By the time I started using it, I was having minimal arm symptoms, so I'm not sure if it helps with downstream pain.

http://en.wikipedia.org/wiki/Cryothe...e_pack_therapy