srodr,
From the US Airways website, http://www.usairways.idine.com/site/...questid=59094, call 1-800-818-8340 to register. I know this is what I had to do to register for US Airways miles. Most iDine airline registration forms are based o the airline's site (or you will be directed to call a number).

Like pinniped, I have multiple logins for my multiple iDine accounts and think it's silly. But it doesn't like they're going to combine multiple accounts anytime soon. Hope this helped!