Not just for steaming crabs:

Vinegar is a liquid produced from the fermentation of ethanol in a process that yields its key ingredient, acetic acid. Ninety percent of American Households buy vinegar. The 4 major uses are for salads, as cooking ingredients, pickling and home canning.

[ 62 Little Known Uses Of Vinegar | because you value your body ]

I've been cleaning the house with vinegar for a while now. Ants seem to hate it, it cleans almost as good as those chemical cleaners, but you know it's got to be better for the environment. I add a bit of flavored oil to mask the vinegar smell a bit, since the wife doesn't much like how vinegar smells. Now I've got a few dozen more things to try my vinegar on.