Are you seeing multiple countries? What we usually do is convert a minimum amount of dollars (enough for at least the first day) into the local currency upon arrival (at the airport). You'll usually get a better exchange than doing this State side. During our stay in the country, we usually will use our bank cards at large, international banks (like HSBC or Barclays). It is easy and the exchange rates usually lower. Then before moving to the next country, we'll convert any leftover currency first. Remember that usually coins can't be converted so spend your change first.
I don't use traveler checks. I do hide money on my person (I always have a U.S. $20 in my bra – if thieves find that, I have bigger problems than losing my cash). However, because we use bank cards, we don't carry a lot of cash.
Do you have to convert to local currency?
Sure, most touristy places will take the American greenback (still, despite all the scare talk). However, they will do so at a premium and expect to get local currency back. Local places like street vendors (yum) and grocery stores (an inexpensive place for souvenirs) will want local currency.
Before we return home, we always convert our currency back to U.S.