Mannitol is the coating used to create Adria's legendary memetic peanut. The el Bulli catalog (2009) says 500g of Mannitol is used, heated in a pan until it melts, and then the frozen peanut cream (molded in the shape of a peanut) is dipped in the melted Mannitol to create the peanut "skin".
I've never heard of Mannitol before, only source I have found is Texturas, which sells this in 700g units for lots of $$$$. Texturas tends to be rather expensive though... does anyone have any experience with Mannitol or know of any non-Texturas branded alternatives?