Add me to those who have used miles to go free to Australia (six times), including on United like Catman! Three years ago, with a UA expiration deadline looming, I decided to take the family in style on UA to OOL (Coolangata), Gold Coast. I was going to use mileage for it it all, but paid for my 7 year old sons ticket when I found out they actually would discount an already discounted ticket as a "childs" fare, even in business and first class. He got the mileage for his trip (almost a free domestic roundtrip) and we used the lefovers to take an extra free trip to Hawaii! It brought him up to PremEx when he was four years old!
My wife and I used miles to go to our wedding in St John, USVI and also for our honeymoon in Bali, Indonesia.
My same 7 year old son used some of his miles on NWA, which WERE due to expire, to buy his mom a trip present to BKK, Thailand last year, so he could return to his favorite city!
We usually try to use much of our mileage for upgrades and for free trips to the islands.