Do you really need to be coding on the bus/train/plane or in hotels? When you go to a meeting, do you really need to bring your entire development setup with you?
When I go into a client's office for a meeting I usually only need to take notes and do presentations. So I get a cheap $500 laptop for that. If I need anything at all from my home workstation, I just remote into it. Actually, I did this even before I was working for myself - I'd just remote back into my workstation at my desk.
Is it just that you don't want to deal with 2 machines? Are you just doing it because that's what everybody else is doing?