It's a Passiflora. I don't know which species. P. caerulea is one that grows wild here. I'm sure someone else can pin it down for you.
Alana

It might be a Passiflora triloba. If you are able to find a ripe fruit I'd love to get a few seeds.

Here is another pic. It may help to know that the leaves are rather large (5-7in) and the branch/stem of the vine is angular, not the typical rounded cylinder shape.

The foliage and flower look like P. triloba but I can't remember if the stem is squared like quadrangularis or not. I haven't grown triloba in several years. Take look at these pics.

Here is a link that might be useful: P. triloba