Thursday 11 December - Boston

US currency is officially backward. First of all, all dollars have are in note form, starting with the $1 and heading upwards in value. What that means is that your wallet can be as thick as the synchronised swimmer who thought she had to drown because her partner did, yet in reality you've got "Jeanne Little" of the "Johnny Cash". Second of all, it's all the same colour, so most purchases involve a complete examination of the wallet to work out what you've got in there. The aussie system of nothing below a Stewie Diver (Fiver) being in paper, and different colours for the notes is much preferable. I miss the look of one's wallets, full of crisp new pineapples (the colour of the $50 note), when you've just taken a small % of a bookie's life savings from him. I've resorted to occasionally filing all the notes in my wallet in order from highest to lowest, to make it easier to find that lone $20 bill amongst all the $1's.

Given you've got to tip so many people - tax drivers, waiters, waitresses, bar staff, bus boys etc. - I've learnt that you need to keep a few $1 notes in your wallet too, which makes every purchase so much more complicated.