OMG ... I thought for a moment you were going to use the "S" word .... stamps !
http://oldcurrencyexchange.wordpress.com/ 1 - well illustrated, links to image gallery on Pinterest 2 - original thoughts + research (re-hashed...
The replies are quite interesting but do not tell the full story. For example, FOUR non-EU countries use the Euro currency and THREE of them...
Separate names with a comma.