Thanks JH4 - i think i will need more.
I'm going away for a week with the mrs and i will see how i get on with 2 4gb sticks.
I thought i can always stick it in easy mode and although a step down in quality you get a lot more recording time and the PQ isn't that different.
Also i like the idea of 4gb sticks i could completely dump the whole card to DVD-R and the mrs can do it without having to think. But i doubt we will be taking a storage device or laptop abroad. So depending on my week away, i will prob end up getting another 4gb and a spare batt as you suggested