Most of you guys seem to have it easy with online/intranet expense systems.
We've to itemize every expense on a spreadsheet - food, transport (not including flights), internet, phone, postage, misc, etc. Each individual item must be accompanied by a reciept. This reciept must be numbered in the correct order and then glued/sticky taped down (not stapled) to a piece of paper and submitted along with a printed and signed copy of the spreadsheet.
I used to get quite frustrated at all the paperwork required for each project (I'm a technical person and don't care for all the associated paperwork) but after a few years it's not so bad as I'll do my expenses day by day, instead of once a week/fortnight.
Luckily we don't have to worry about expensing back flights or accom!