I went to the UK last month with two 32GB CF cards and two 16GB cards. I figured that would be plenty. Not so much. The last night I got caught out with no more space and had the Tower Bridge all to myself. Luckily I had been dumping content to my laptop daily and backing up to an external, so I was able to format a CF card and use it. But I really wanted to keep 3 copies of all my images until I got home (CF, laptop, external).

Guess I need to buy more cards before the next trip.