Having done a bunch of reading I'd like a few things clarified.
1. Is it possible to have iPhoto shared between 2 user accounts equally (that means that each one can edit and add photo's)?
2. Will it work seamlessly? If not what problems will I encounter?
3. Is it better to do this from an external drive?
I'm using what was, until yesterday, the latest version of iPhoto. Obviously with iLife '09 - iPhoto may act differently but I'll cross that bridge if/when I upgrade.