Successful collaborative consumption requires a clear understanding about the details of the arrangement. Where will the shared item be stored? Who's responsible for maintenance? What about insurance and liability? You may decide casual, over-the-fence conversations are enough, but sometimes a more detailed agreement makes sense. Simple contracts freely available online can help define the terms of the collaboration.
Cheapism.com rounded up a robust set of goods and services that can be shared for savings all around. The possibilities are endless, but this should help jumpstart your frugal imagination.