When I was living in Camiguin from 2002 to 2004, it was the greatest wish of everybody on the island, locals and foreigners alike, that Camiguin would finaly get an ATM Machine.
The first machine came in 2004 but only for local ATM Cards and Landbank customers and not for international Credit Cards. I don't know how many customers I lost for my Dive Center because people simply could not get their money. Terrific!
Since a few years now and with the introduction of broadband Internet connectionon on the island, Camiguin has ATM machines, even for international Credit Cards. But since I know the reliability of broadband DSL in the Philippines, it wouldn't hurt if you bring in some cash money from Cagayan de Oro or Cebu. Just in case...
You will find the ATM machines in Mambajao, at the Landbank and the Bank of the Philippine Islands (BPI).
If you want to bring in foreign cash money, make sure to bring US Dollars. You can also exchange Euros but the exchange rate is bad. You can exchange your money at the BPI, Landbank, some Pawn Shops and in the big Salcedo Super Market in Mambajo City. Some of the resorts might also change some money but watch out for the rate.
Traveler Cheques are a big problem all over the Philippines. If you take them to a bank, you will start a big circus with copies of your passport, copies of the cheques itself, signatures of the bank manager and much more. There are only a very few travel offices and money changers who give you money for traveler cheques without making big problems. For Camiguin I would recommend to change cheques for cash before going on the island.