... just buy a pay-phone card ... good ol' times
Indeed. I hadn't thought about card-operated phones when I posted. I was only thinking of coin-operated phones. I may have used a card-operated phone since 2005, although I can't remember exactly. I know I used quite a few of the TelMex phones in Mexico on my various trips there, and I've used them in Central and South America as well. Can't quite remember when.
Of course I still don't take a phone with me when I'm traveling. We were in Aruba for ten days this summer and I didn't take my mobile phone with me. Last year we spent a month in China and I didn't take my phone. These days my wife and son are with me when I travel, so there's no need. If it comes up that I need to call them, like I'm at the dive shop or whatever and we're running late and they should just have lunch without me, I just borrow their phone and leave a message at the hotel.
I think I have never seen a coin-operated public phone anywhere around here in Austria, only card-operated ones. Despite the fact that I'm "already" 27, I think the card-phones were introduced in the early or mid-90s, which explains it.
When it comes to travelling, I took my unlocked mobile phone with me to the US in 2011 and bumped into the local AT&T shop at the Empire State Building to get a pre-paid SIM-card. It only costs 10 US-cents to call to Austria (ca. 7 €-cents). This is much better than taking my Austrian contract-SIM to the US, because with that one I would pay roaming fees (2$ for the call to Austria !!!), which would make no sense.