I am thinking about getting a prepaid credit card for my trip in Gran Canaria (Canary Islands, Spain).
Are these widely accepted in the region?
According to the tourist site Spain-GranCanaria, you'll be fine. However, you'll need to show ID as well when you pay with such a card.
The use of major credit cards is widespread among local shops, making shopping easier. This is also the easiest way of having money without having to carry large amounts of cash, which minimises the damages in case of loss or theft. Credit card holders, and indeed debit card holders too, will need to present a valid picture ID however when purchasing goods with a card, like a driving licence or passport.