Bean asks Also, why do we use dollars in Canada and not pounds (ditto for Australia)?

In Australia we initially adopted the British pounds-shillings-pence system which was in use until decimal currency was introduced in 1966 (14 Feb 1966 to be exact - I can still recall the TV ads with a cartoon character called Dollar Bill). I presume they chose "dollar" rather than "new pound" or some such to avoid confusion.

1 pound converted to 2 Australian dollars. Initially there were 1c,2c,5c,10c,20c and 50c coins, then notes for $1, $2, $5, $10, $20, not sure about higher denominations. [As an aside - 50c coins were initially pure silver, but when the value of the coin dropped below the value of the silver people started melting them down, so they changed the metal!] Many years ago when inflation had eroded most of their value, the 1c and 2c coins were phased out. Prices are still quoted to the nearest cent but totals are rounded to 5c. The next development was replacing $1 notes with coins, then $2 notes with $2 coins. Like Max I rue the fact that they opted for a $2 coin smaller than the $1. Then came plastic notes instead of paper. Oh and there are also $50 and $100 notes (and probably higher but I never see them!)

The old names bring back faint memories for me :-
florin, shilling, sixpence, threepence (pronounced throopuhnce with a short 'oo'), penny, halfpenny (pronounced hayp-ny) and farthing (=1/4 penny; this one was out of circulation in my time). Some of these had nicknames too - "zack" (sp?) is one that comes to mind, but I don't know which one it is.

But what the heck is a "rahzoo" (sp?), as in "I haven't got a brass rahzoo"? Is that a widespread expression?