Pickled garlic is very refreshing in hot weather and is a food that will keep for a weekend without refridgeration.  They also make a nice addition to the snack tray at parties.
 

Pickled Garlic 6 whole heads of garlic1 1 1/2 cups vinegar2 1/3 to 1/2 cup sugar3 1/2 teaspoon salt 1/2 teaspoon peppercorns 1/2 teaspoon mustard seeds 2 whole cloves 1 bay leaf

Peel all of the garlic and put to one side.  Put all of the ingredients except the garlic into a large pan and boil for 2 minutes. Then add the garlic and boil for a further 2 minutes.  Carefully pour into a large sterilized jar, seal firmly and store in the refridgerator for 4 weeks before using.

1. If you really want to make this in quantity, say for a feast or dayboard, large containers of peeled garlic may be found at "warehouse club" type stores that deal in institutional quantities.
2. The choice of vinegar is really up to you.  you will not want to use too subtle a vinegar because the garlic will overpower it, however white vinegar can be very harsh.  Personally I would opt for wine or cider vinegar (1 1/4 cups) with a small amount (1/4 cup) of balsamic vinegar added for flavor. 
3. The amount of sugar is very much a personal choice.  I like my pickled garlic to be tangy so I opt for less sugar, your personal taste might favor a sweeter pickle.