How about making some "Sweet & Sour Fresh Lime Pickles"?

Ingredients:
1) 20 fresh limes (approx. 2 lbs.)
2) 1 cup sugar
3) 1/4 cup pickling salt
4) 1 1/2 - 2 TBS. cayenne pepper (or to taste)
5) 2 TBS. caraway seeds coarsely ground - optional
6) 4 cups fresh lime or lemon juice - approx. 20 limes/lemons
7) 1 small piece of muslin or 4 layers cheesecloth - enough to cover the mouth of a jar

Directions:
1) Wash and dry the limes. Cut each one into 8 wedges and put in a large sterile glass jar.
2) Put in the sugar, salt, ceyene pepper, and seeds.
3) Cover the jar with your palm, or a lid, and shake vigorously to mix.
4) Uncover and add the lime/lemon juice and shake jar again.
NOTE: the juice should cover the limes by about 1/2". If not, add more juice.
5) Cover the jar with the muslin or cheesecloth securing with a rubber band.
6) Place in a warm sunny spot in your kitchen or outside in the sun. (If the pickle jar is outside in the sun, bring it inside at night).
7) Shake the jar once or twice a day until the lime wedges are soft and light buff in color and the juices are thick. (approx. 15 to 20 days).

This pickle stays fresh at room temperature almost indefinitely. Enjoy the fruits of your labor!!

VARIATION:
Add fresh green chili peppers (such as Serranos) and thinly cut fresh ginger strips.