our U.S. taxable income. As such, cash taxes paid were $53 million, $24 million, and $15 million for 2008, 2007, and 2006. As our federal and state net operating losses and tax credits are utilized, cash paid for taxes will increase. We endeavor to optimize our global taxes on a cash basis, rather than on a financial reporting basis. 

In February 2008, our Board of Directors authorized a debt repurchase program, replacing our previous debt repurchase authorization in its entirety, pursuant to which we may from time to time repurchase (through open market repurchases or private transactions), redeem, or otherwise retire up to all of our outstanding 4.75% Convertible Subordinated Notes due 2009 and 6.875% PEACS. In 2008, we called for redemption all of the remaining principal amount of $899 million of our outstanding 4.75% Convertible Subordinated Notes. Holders elected to convert $605 million in principal amount of the 4.75% Convertible Subordinated Notes, and we issued 7.8 million shares of our common stock as a result. We redeemed the remaining $294 million of the called principal amount for cash. At December 31, 2008, the debt balance of our 4.75% Convertible Subordinated Notes was zero, and the debt balance of our 6.875% PEACS was $335 million. 

In August 2006, our Board of Directors authorized a 24-month program to repurchase up to $500 million of our common stock, pursuant to which we repurchased $252 million and $248 million of our common stock in 2006 and 2007, respectively. In April 2007, our Board authorized a new 24-month program to repurchase up to $500 million of our common stock, which was replaced in February 2008 by a 24- month program to repurchase up to $1 billion of our common stock. We repurchased $100 million of our common stock in 2008 under the February 2008 Board authorization. 

Since our 6.875% PEACS, which are due in 2010, are denominated in Euros, our U.S. Dollar equivalent interest payments and principal obligations fluctuate with the Euro to U.S. Dollar exchange rate. As a result, any fluctuations in the exchange rate will have an effect on our interest expense and, to the extent we make principal payments, the amount of U.S. Dollar equivalents necessary for principal settlement. Additionally, since our interest payable on our 6.875% PEACS is due in Euros, the balance of interest payable is subject to gains or losses on currency movements until the date of the interest payment. Gains or losses on the remeasurement of our Euro-denominated interest payable are classified as “Other income (expense), net” on our consolidated statements of operations. 

On average, our high inventory velocity means we generally collect from our customers before our payments to suppliers come due. Inventory turnover was 12, 13, and 13 for 2008, 2007, and 2006. Inventory turnover has declined slightly over the last several years, primarily due to category expansion and changes in product mix, and our continuing focus on in-stock inventory availability, which enables faster delivery of products to our customers. We expect some variability in inventory turnover over time as it is affected by several factors, including our product mix,