For my sins I've read about the chocolate Jesus, but who is this Elijah and why should he be enshrined in jello? ;)

Linky, Elijah is an Old Testament prophet, believed by Jews to be the harbinger of the messiah. At Passover, a cup of wine is set out on the table for him and the door is left open for him, all in hopes that he will come to announce the coming of the messiah. As for the jello, well, since Passover desserts are traditionally lacking (in quality, if not quantity) due to the omission of leavening agents and regular flour, many of us can relate to jello-mold (in a Bundt- or tube-shaped mold) for dessert at this holiday, in addition to the traditional stewed fruits.