I have taken travelers checks before, and found they become a hassel.
First you have to get them at the bank, then "sign" them, then "try" to find someone that will take them. What I do, is take "large" bills of cash as they don't take up much room. (I also put this in the safe when I'm not carrying it with me.) That way, you can always go to the Purser's desk and have it broken down to smaller bills.