My niece, who used to be married to a Filipino guy, turned me on to opo as a soup/stew ingredient. I can find these things for a fairly high price in most LA-area mainstream supermarkets, or for a whole lot less in the Asian and Latino stores. If you don't know what this is, it's a sort of squash- or gourd-looking thing, shape a tapering cylinder 10-14" in length, smooth thin skin and pale green in color. The flesh is a sort of damp pith - I doubt that it's edible (or perhaps just palatable) raw, and it really hasn't any flavor to speak of, but it cooks to a pleasant, slightly fibrous consistency and absorbs flavors very well. I don't know what else it might be called, or anything else about it, but I'm curious to learn as much as I can, and so far Google and everyone else is coming up blank. Anyone know more about this?