We generally hedge currency risks of non-U.S.-dollar-denominated investments in debt instruments with offsetting currency borrowings, currency forward contracts, or currency interest rate swaps. Gains and losses on these non-U.S.-currency investments would generally be offset by corresponding losses and gains on the related hedging instruments, resulting in negligible net exposure.

A majority of our revenue, expense, and capital purchasing activities are transacted in U.S. dollars. However, certain operating expenditures and capital purchases are incurred in or exposed to other currencies, primarily the euro, the Israeli shekel, and the Chinese yuan. To protect against reductions in value and the volatility of future cash flows caused by changes in currency exchange rates, we have established balance sheet and anticipated transaction risk management programs. Currency forward contracts and currency options are generally utilized in these hedging programs. Our hedging programs reduce, but do not always entirely eliminate, the impact of currency exchange rate movements (see "Risk Factors" in Part II, Item 1A of this Form 10-K). We considered the historical trends in currency exchange rates and determined that it was reasonably possible that a weighted average adverse change of 15% in currency exchange rates could be experienced in the near term. Such an adverse change, after taking into account hedges and offsetting positions, would have resulted in an adverse impact on income before taxes of less than $35 million at the end of 2007 and 2006.