You can find horizontal:
photo by SEWilco
and vertical sundials:
this one's in Paris. Photo by Ken Eckert
This one from New South Wales is a whopper (though it doesn't seem to be doing much good at the time of the photograph):
Singleton sundial. Photo by Bandworthy
My very favourite sundial is the topiary one at Ascott House in Buckinghamshire, England (follow the link to see a photograph). Around the clipped box numbers is the motto, also in clipped box hedging, Light and Shade But Love Always.
If you don't know where to find a sundial then if you have any sort of stick to cast a shadow you can make your own very easily. It'll only tell the correct time at that particular place at that particular time on that particular day of the year, but, hey, that's better than a clock which loses a second a day.
Or, of course, its battery.
Spot the Frippet: sundial. The Old English for sun was sunne. Dial comes from the Latin diālis, daily, from diēs, which means day.