What's the best backpack a geek can buy?

Who makes the world’s best backpacks (or rucksack as we call them in the UK) for (mobile) geeks? I’m looking for a recommendation.

You know, something that’ll carry a laptop, maybe even charge it via a solar panel, lots of pockets for phones and iPhones… integrated headphone loop or something like that?

What’s the absolute pinnacle?

Any ideas?