Some issuers used to offer rewards (not sure about miles) for BT's, but as far as I know the only one who still does is your first BT with a new GM card. I'm pretty sure you can't get miles for a BT.

On a happier note, there are a lot of cards offering 0% BT on new cards. I know Bank One and Citi among others. Check out www.fatwallet.com. I myself have $150K in 0% BT's.