More than once. The most catastrophic was when the rear end locked up on our Jeep Cherokee. I was on the Apache Trail near Roosevelt Lake and had it in 4x4. The entire drivetrain was shelled in one big BANG. Not pretty. It was a fishing excursion with my son when he was little. We didn't get much fishing done, but we made the best of it.
The most annoying was on a road trip up and down I-5 with the family. We had the truck loaded with camping gear and bikes on the back. It made it from SoCal to WA nicely, but then threw the belt. I had a spare, so put it on quickly and we were off. As we headed south from a nice couple of weeks in WA, it shredded. Then it happened again. Around San Fran it happened again. I have a friend there, so we called them and stayed the night so I could fix it again.
Finally, fixed, we headed to the Golden Gate Bridge. Just a few miles before it went again, but took out the power steering line in the process. We nursed it to a repair shop where a nice mechanic let me borrow his tools and order parts through him, since I really wasn't wanting to pay someone to do what I knew how to do.
We couldn't find the reason it was happening though, so I went to my friend's house again and we deliberated. Finally, we took it to a mechanic to look at it. After fiddling around a bit, he found a loose pulley on the brand new power steering pump. It was subtle, but just enough play to cause the belt to skip a groove every now and then. And apparently it was getting worse.
The original mechanic down in LA wanted me to nurse it home. I had my family with him, so chose to get it fixed and let him pay me back. I felt bad, but who wants to get stranded between towns on the interstate? We didn't even bother to try the GG bridge again, so we've never seen it. :)
It was an adventure though. When all is said and done, it adds another story to our lives, we met some new people, made some new friends and we got to spend some time with good friends that we wouldn't have otherwise.