the sun is of course, not cooperating today, so they are not actually showing the time.
if you are into making your own, here's the page that shows six types of sundial.
LINKY, including the diptych
these are many other types of sundial, and many unusual portable ones, google for more info....
edited:
found an online cc. of an optical one like mine actually in the sun
someone actually makes a digital sundial:
quite clever, i'll have to buy one of those i think. uses fractal geometry to make thin optical filters in the upper section that illuminate as mirror imaged digits which reflect correctly in the base mirror.
if you have a large garden, here is a fun one, the analemmatic,
which can be made in simple stepping stones like above. YOU are the gnomon, as in this one:
you stand on a sliding scale that corresponds to the month
there was a website that will calculate the plans and let you print it out, depends on location. there are also some freeware and shareware progs that calculate & let you print plans for a wide assortment of sundials for your house or garden. or your pocket