I realised something today and I don't know if it's common knowledge. Ryanair quote flight prices in euros on their website, but when it comes to paying, if you have a UK credit/debit card, they switch the price you're about to be charged to pounds.
Now unless you've checked the €/£ exchange rate that day you might not realise what a massive gouge they're about to take out of your card, but today the difference the real exchange rate and their rate was £50! Yes, they were about to get £50 for free, and it's so easy to miss that little bit on the payment page. You have to click to open a little pop-up and un-check the box to say that you want to pay in euros. Nice little trick Ryanair. I wonder how many people don't even realise they've been ripped off!