I've always been interested in sculpture that is cast in an odd material, like salt or sugar. I think it's because growing up we always had a series of Roman salt sculptures that my dad had brought back from Italy while he was in the Navy. I remember wondering how they were made and whether or not they were really salt (Yes, they were. I remember licking one as a "test" of this fact.)
Seeing the post by the fabulous JL Schnabel on Hi-Fructose about Fernando Mastrangelo brought back all these memories (without the desire to lick them) as he is casting his work in things like sugar, salt, corn meal and gun powder. Check out his website for more info.
Images from here.