If your doc doesn't want you immobilized, then a clavicle strap is a good way to go. It supports your AC joint without freezing up your arm. A few years ago, when I got an AC separation (fell off the mountain bike), wearing the clavicle strap made it so I could go back to work.

Here's a picture of one: http://www.kneeshop.com/proddetail.a...20500X&cat=413