euros or kn in Croatia?

Kuna.

Most stores in Dubrovnik were willing to accept both, but we did the math after a couple of transactions, realized we were paying between 10 and 15 percent more in Euro and went to change money over into the Kuna.

Thanks for the posts. I must get a new RS guidebook. Mine on Croatia and Slovenia is 2008. I thought maybe they'd transitioned to euros by now.

Valerie's experience points up the general fact that when you're traveling outside the US, it's ALWAYS better to use the local currency, and to obtain it from local ATM's. You may find individual merchants that will accept non-local currencies, but in those cases it will be the merchant determining your exchange rate, not the interbank network. And the merchant's exchange rate will always be skewed in his favor. You cannot get a better exchange rate that that given to you by local ATM's.