When we had reservations at Beach Club for breakfast, we just took a taxi. The tax ride from Pop Century to Beach Club was only 8.25 and only took about 10 minutes. Best $10 I spent at Disney!! I had called the taxi 30 minutes ahead of time thinking it would take them a while to get there. When we went outside about 10 minutes early, he was there waiting on us. Apparently they're located very close.
Oh, and if you have an early breakfast at Contemporary, Polynesian or Grand Floridian, if you catch the first bus, it will take you directly to the hotel. They did for us last summer anyway.