I know you can get it commercially. I haven't made mousse from scratch since college. At work, we always use a mix, which I can remember using some made by Jell-O.
Actually, I just made some White Chocolate Mousse yesterday, folded in some white chocolate crumbs, a little Triple Sec, and spooned it into ready-made pie shells, then froze. I'm going to cut and plate them for a party on Friday. Of course, I made enough for 80 :)
Peace, Love, and Vegetable Rights!
Eat Meat and Save the Plants!