To freaze, I would cut them open, scoop their bits into ice cube trays then freeze them. Once frozen I would put the passion cubes (oo doesn't that sound naughty) into zip lock freezer bags or a container and they should keep for a month or 2.

Lemon juice done this way is good for 6 months+ but I usually use it all before 6 months is up so not sure how long.

Oh and those little bits of wine left in the bottle can be frozen like this to add to sauces etc when you need them, saves opening a whole new bottle... then again open the new bottle and enjoy drinking the leftovers