People like you and I are a bit ahead of the technology curve. I am constantly traveling (mostly for fun) around the world. What we need has not really been created yet. The technology is here, but companies like Apple would rather bleed us to death than give us the ultimate device now. I can't blame them though. I would do the same thing if I were in their shoes.
* I use a simple 12" laptop. The new Macbook Air is making me drool. Lighter is always better. However I can't afford that now.
* I have the new iPod 160 gig. Fantastic! Big storage and battery life in one. Thank you very much Apple! :)
* My telephone is a simple smart phone I would prefer the new Nokia N95 (smart phone, wifi, 5 mega pixel camera, and GPS all in one), but I can't afford it (traveling a lot keeps you poor in wallet, but rich in life).
- the perfect device would be the 3rd or 4th generation iPhone. It should have have GPS, 5+ mega pixel camera, wifi, 3G, and 100+ gigs of storage. All-in-one! They can do it now, but they won't.
Unlike you, I have an added disadvantage. I am a photographer, so I have a dSLR with 3 lenses. It is a pain in the butt to take around. Consider yourself lucky you don't need to carry one of these things.
My best advice is to get used to carry more weight. Build up your mussels a little. ;)