On a recent trip to Hyannis, some friends and I stopped at Caffe Gelato Bertini for dessert. I tried the Cape Cod Beach Rose and the Zabaglione. The employees (whom I assumed to be the owners) happily explained the flavors. Beach Rose is made from rose petals and tastes exactly as you would expect--- like roses. It as strange at first, but quite delicious. The Zabaglione has orange and pine nuts (if I'm remembering correctly). It, too, was delicious. They, of course, had plenty of "normal" flavors. The owners were very nice and seemed to enjoy answering my questions about their gelato and Cape Cod. I highly recommend stopping in if you're in Hyannis.
(I accidentally clicked "bar scene" and couldn't unclick.)