G e o_s y n_c h r o n i_c i t y

BIG MONEY

You might be forgiven for thinking that this $5 billion "special agro-cheque" from Zimbabwe is the largest denomination banknote ever issued. (It's valid from 15/5/2008 until 31/12/2008, worth roughly UK 7p as of 27/7/2008 I'm told, and available on EBay for considerably more in Uncirculated condition.) Far from it: the same country currently has a $50 billion note. Surely that must be the largest, then? No, though things may be heading in that direction, and "agro" may be the biggest thing that these banknotes generate. (Latest news as of 30/7/2008: Zimbabwe is about to slash 10 zeroes from its money...)

The largest denomination banknote WITH zeroes to date was issued in Yugoslavia in 1993, 500 billion dinar (5x10^11):
http://www.3833.com/largest_denomination_wbn_with_zero

The largest without zeroes (they had to leave some space on the paper for description and illustration, I suppose) was issued in Hungary in 1946, a 100-quintillion pengo (10^20) monster:
http://www.3833.com/node/1125

However, things are certainly bad enough in Zimbabwe now. For updates, see:
www.zimbabwesituation.com
where, among other things, you can learn of the latest exchange rate -US$1 Fri 25 July 2008 = Z$700 billion. This is "A 3400% increase in 5 weeks or 139900% since 23 May (2 months)".