Chowhounds do much more with pineapple juice than just drink it; they also cook with it, in dishes both savory and sweet.
laliz makes a dressing for fruit salad by mixing 1 tablespoon cornstarch and 3/4 cup pineapple juice in a saucepan until smooth. Bring it to a boil, cook and stir for 1 minute or until thickened, then cool.
tochipotle makes mango chutney by mixing pineapple juice with chopped mango, orange pepper, red onion, a little garlic, cilantro, and jalapeño, and says it’s a “really great fresh, flavorful addition to fish or pork.”
Board Link: what to do w/ pineapple juice?