I recently read an article in the Wall Street Journal that described how Wal-Mart Cuts Taxes by Paying Rent to Itself (I had to link to an anti-Wal-Mart site because the WSJ Online is subscription-only).
Granted, Wal-Mart isn't the only company using this tactic, but they're an easy target and that's why I'm assuming the WSJ published the article about them in particular. Regardless, I find it pathetic that businesses will knowingly partake in such shady undertakings.
Perhaps even shadier is Enrst & Young -- Wal-Mart's external auditor -- which originally proposed and sold the the strategy to Wal-Mart in the first place.
I could bore you with a few paragraphs summing up the strategy, but it's a lot easier and simpler sharing this graphic, taken from the WSJ: