Continuing yesterday's astronomical theme, here's a wonderful prop sundial for a world with two suns from artist Tim Baker.
Twigs. Twine. Paper. Well, that and a heaping big helping of creativity and inspiration.
Something like this would fit right in at a live-action game. A variety of Pacific Islander cultures used intricate arrangements of wooden sticks tied together with natural fibers to serve as maps and navigational aids. Mr. Baker's sundial is just the kind of thing a tribe with close connections to the Mythos might create as part of a ritual, either as a protective device...or as an aid to summoning.