Most merchants in East/SE Asia don't accept USD directly, you must go to money changer to convert to local currency first. I travel to Asia 2-3 times/year. There are countries that use USD as legal tender, like Panama. Tourist trap locations are also more likely to take USD currency.
Never change your USD at the airport, except for a small amount to pay for taxi and tip. You get much better rates at money changers in the malls.
In emergencies, you can insert your US ATM card into ATM's overseas and withdraw in local currency. It doesn't work with all ATM's, look for the ones with Star or Plus logo. The exchange rate isn't always good but it's easy.
USD has depreciated by quite a bit since 2000. Had you deposited your $ in Euros, Canadian dollars, or Gold/Silver coins, you'd have came out ahead. If you're taking USD overseas, your money ain't getting you as far as it used to. i.e. in Malaysia it used to be RM 3.8 : 1 USD, now it's RM 3.5 : 1 USD I think.
If you don't want to play currency, you can still buy mutual funds that invest in European, or at least global stocks. They did very well in recent (2003-2006) years, much better than US domestic stock funds in most cases, except for some sector funds like REIT's.
I'll be visiting the Philippines this year... the exchange rate was around PHP 55 : 1 USD last year. Right now it's PHP 49 : 1 USD.
It's like losing 12% of your money's value before you even arrive in Manila.