Originally Posted by anniegb
Trip - absolutely people buy surplus currency from each other - avoids bank commission.
Reason for carrying 2 cc - same as yourself one to use and one for security.
We were glad we had a second credit card on our Med cruise. We had reported a simple instance of a double charge, and specifically said it was just an error and NOT fraud, and specifically been told it was not necessary to cancel the card.
Then in the middle of the Mediterranean the cruise line told us our card had been cancelled!
The ship was so kind as to allow my wife to make a phone call to the CC company. It would have been expensive otherwise as she spent about 45 minutes with them trying to get it straight. Finally they agreed to deliver a new card to us two days later in Istanbul! Then they wanted us to go pick it up instead of sending it to the ship.
Fortunately we did carry a backup card.
As far as the original question --
I carry about $100 in ones and fives for tips to baggage handlers and so on.
DW carries $200 in tens and twenties for casual shopping.
If we have an independent tour that wants cash payment, I put the amount plus a tentative tip in a separate envelope which stays in the safe in our cabin.
Otherwise it is credit card all the way! We normally stick strictly to the tourist areas and everybody takes them. We rarely change to local currency unless we are going before or after and need cab fare and such.