For some people this tiny, tangy citrus fruit is the key to happiness. And there's no better place to buy joy than the source -- the Tree itself -- where the shelves are dedicated to products flavored with this coveted concentrate: key lime-covered pecans; key lime-frosted graham crackers; key lime marmalade; key lime jelly beans. Diehards can even wash their hair with key lime shampoo and bubble up their baths with key lime soap. But the most obsessed among us probably won't even make it into the shop, given that the patio area contains dozens of potted key lime trees. The three-gallon containers go for ten bucks, and while you might not see limes on the limbs for a few years, it's a good investment nonetheless. Just keep it to yourself. We wouldn't want the canker crowd to get aromatic wind of it.