You should always take some cash with you, and that amount depends on how safe you feel in that particular country. But you can seldom carry enough to cover your whole holiday, so cash cards or cash passports are as essential as travellers cheques once used to be. These are good if you want to lock in particular exchange rate if you think it’s only going to get worse (this is their major advantage over the Internationl credit cards mentioned in a companion article), and they’re much safer than carrying large amounts of cash around with you. The disadvantages are that you might not get as good an exchange rate as with cash, and there is usually a commission of 1% approx whenever you put money on these. Most charge an initial fee of $5-15 and a closing fee of $0-10 (some charge both), and most charge a monthly inactivity fee if you don’t use them for 12 months ($3-4/month).
There are many cards, but I’ll just concentrate on the ones I consider offer the best rates. These can both be purchased online.