it's called www.kauaiabundance.com
this one is just for kaua'i residents, but the concept is great! people who got some extra veggies and fruits, perhaps venison too, to give away, can post there and people who need food or have some to swap can also post.
perhaps one exists here already or someone with computer savvy (more than i got) could start this here.

Aloha Kau:

Agreed. This custom is, in fact deeply linked to the most traditional spirit of aloha, in which each member of the kauhale ("local family clustering of dwellings", although the term is now sometimes used to denote a small community or hamlet) contributes what one can and receives what is available. The reciprocity process is an important part of this ancient custom and although each 'gift' is in theory offered without conditions, the unspoken social expectation is that a reciprocating act of equal value or quality will be made on the part of the recipiant. Similar customs are found in many Far Eastern cultures.

This is a very important part of the ancient Hawaiian system and it is an important expression of the culture of social collectivity that prevailed in Hawaii until Westerners came to the islands and introduced the capitalist system of production by paid laborers and and consumption of goods by purchasing customers (for currency).

There is no reason why the essentially 'collective' nature of the old system could not be reestablished on a larger scale, other than the fact that many of the residents of the island are not now all year-round, permanent residents, and therefore may not be inclined to take part in such localised subsistance economies.
The old custom exists now among some kama'aina (long time residents) and locals and it is a wonderful (and very practical) aspect of the ancient culture that has still not entirely vanished.

Me ka aloha pumehana! (best wishes)

Kalikiano

we noticed lately that residents here bring each other foods which they grow, fish, hunt and others return the favor in some way by giving a service or some lumber or household effects in return. this is a good preparation for what may be hard times. people in rural areas have a better chance to survive than in cities. i remember this from germany in and after ww2. it feels good and neighborly to help others in some way. the blessings will return and we make new friends. i love this island! one mango and papaya at a time. :)