okay I am going to say it...
Where is the iphone in that list?
But seriously. At least half of those gadgets are only really doing something that one phone (dare I say the iphone with a few extra apps installed) can do in one?
Listen to radio, watch tv (well vids at least at the moment), GPS, take video (again with extra App).
That way you don't need the great big rucksack
// disclaimer. I KNOW the iphone is far from perfect. I am just illustrating a point about taking one nicely built smart phone out with you rather than a tonne of gadgets.