Last year I was stung with a £75 data charge for using my iPhone in Switzerland to navigate out of a mountain area (via Google Maps). Shocked at the charge, I phoned o2 and moaned, and then promised myself not to use data downloads again when abroad.
While in France last week I had to use my iPhone to download email and send a quick message, or let someone down. I used the phone for about five minutes and was charged over £11 for that short period:

Data charges in Europe are crazy, o2 please lower your rates; in comparison to the phone call charge (on the bill) they are not fair.

