A hint for anyone arriving in Spain (or Europe) without Euros. It has been my experience in 2 trips this year that the cash machines have been dispensing only 50 euro notes when you get round numbers. Due to the fact that cabbies, metro ticket booths and small shops don't take 50's, you should get an odd number like 90 or 190 Euros when getting cash so you get some 20's. The smaller bills will come in handy.

Good point about having small euro bills handy. If you are just arriving in Spain, it is also good to have some small change for tips, etc. by breaking one of the bills at a newstand or cafeteria. I've used several ATM's at BBVA bank facilities (including the one at Barajas airport) & when I withdraw 300 euros, I've been given 4 fifties & 5 twenties in every case.

My usual first stop in the airport is a Tabac where I buy a Telefonica Phone card (the kind with the I/C imbedded in the card). They break a 50-Euro note and I'm on my way.