Many use barter credits as currency, so a plumber who needs to have a cavity filled doesn't need to search for a dentist's office with plumbing problems to make a deal.

CNN: Making no-cash deals with neighbors

Sinusitis is inflammation of the nasal cavity and the sinuses, which are air-filled spaces located primarily in the jaw above the upper teeth and in the forehead around the eyes.

CNN: What can I do for my chronic sinusitis?