SFist Lev recently waxed poetic about the same thing just last week, but we came across this site devoted entirely to shadows that give the illusion of penises. CockShadows, billed as "the number one site on the internet for all of you cock shadow needs," showcases images of light hitting objects made to appear male reproductive organ-ish, with end results that are delightfully penis-y. Har!
Anyway, you know what to do: send them your (ideally hung but not required, because, you know, it doesn't matter to us, baby) images, pronto.