Just occasionally I know I'm heading off somewhere I could do with Google maps for, but where data is either hugely expensive (overseas), or not available (North Wales, planes, down a well).

Luckily you can take screenshots with the iPhone, so an easy solution for cheapskates like me is to take a bunch of screenshots of the relevant map screens in before you leave the free data area.

Works for web pages too if you can't be bothered with the iPhone's fiddly cut 'n paste.