On fun or scenic rides I also always carry a camera!
It's fun on the Chilly Hilly to get pics of all the bikes on the ferry on the way over.
Also, if you stand on some of the hills and get shots looking backwards at people climbing up the hill you can get angles that look massive (much worse than they really are). Great for impressing the out-of-towners when you post your ride pics on BikeForums.