Prospectus excerpt:  We are offering 3,000,000 shares of our 6.25% convertible perpetual preferred stock. The annual dividend on each share of convertible preferred stock is $6.25 and is payable, when, as and if declared by our board of directors, quarterly in cash, common stock or a combination thereof at our election, in arrears, on each March 15, June 15, September 15 and December 15, commencing on September 15, 2009. Each share of convertible preferred stock has a liquidation preference of $100 per share and is convertible, at the holder?s option at any time, initially into 2.3033 shares of our common stock based on an initial conversion price of $43.4163 per share, subject in each case to specified adjustments as set forth in this prospectus supplement. The convertible preferred stock is not redeemable by us at any time. If a fundamental change occurs, we may be required to pay a make-whole premium on convertible preferred stock converted in connection therewith, as described in this prospectus supplement. On or after June 15, 2013, we may at our option cause all outstanding shares of the convertible preferred stock to be automatically converted into that number of shares of common stock for each share of convertible preferred stock equal to $100 divided by the then-prevailing conversion price if the closing price of our common stock equals or exceeds 120% of the then-prevailing conversion price for at least 20 trading days in a period of 30 consecutive trading days.