I bought some passion fruit juice by accident at a Brazilian market ... I couldn't find the English on the box of juice, so I bought it out of curiosity.
So, I've been adding it to things.
Passion fruit pairs WONDERFULLY with champagne. It is crisp and refreshing. Champagne brings out the citrus in passion fruit and it was almost like grapefruit without the bitterness. And let me tell you this pairs delicously with chocolate ... bunny ears.
I guess I didn't discover this as there are a few mentions on the web. The proportions are 1 part passion fruit juice to 2 parts champagne.
Some people use puree rather than juice. Martha Stewart trumped me and used fresh passion fruit (link below).
Googgling to see if this was common or not, one good suggestion I need to try is putting passion fruit juice in iced tea.
Passion fruit juice isn't very good with lambrusca though. It brought out a strange sweetness.
It is a pretty good juice all by itself.