Originally Posted by
Nagasaki Joe
Glad to hear about the value of these old notes as I have a bunch of 100-yen notes at home along with a few 1-yen notes and a 10-yen note (photographed below). I'll have to have the value of these assessed, as they could be worth a pretty penny with the right dates on them. The U.S. government also recognizes al
l circulating notes issued from 1861 to the present at face value as legal tender. When I was a kid, my grandparents gave me silver dollars as presents on birthdays and on Christmas. I had collected 30 of them over the years but my parents were unwise and deposited them in a bank account for me and all I could get back were relatively worthless federal reserve notes or silver certificates (supposedly redeemable in silver, but no longer so since the 1960s). 
Old Japanese currency notes
After a little searching, I also found this Japanese-Malaya occupation currency (sometimes called "Banana Money"), a $10 bill printed in English and curiously denominated in "Japanese dollars." I don't think the Japanese government accepts this as legal tender in Japan, but it apparently has some small collector value.
Japanese-Malaya $10 bill printed in English The reverse side of the $10 bill
Some of those are in nice shape!
I worked at a bank in uni and once someone dumped a dozen silver dollars (from early 1960s) in front of me. I could tell by the sound they were real. Needless to say I swapped them with my own personal cash later that day.