Hey guys, I would very much like to implement GTD in my life, but the importance of having a "home base" where I have an Inbox and process it is emphasized, giving me a problem. I spend about 50% of my time in a cubicle, 20% of my time on the road in my car on various-length trips, 20% at hotels/peoples' houses/wherever I'm traveling to, and 10% at home (typically just enough time to read for an hour and then pass out for a solid 3-5hrs sleep).

After a lot of google searching, I'm not finding a lot out there that is customized to such a mobile lifestyle, short of getting an iPhone, blackberry, or palm device, which I cannot do at this time. What other tools are fitting for such a variety of environments, with no real consistent home base in which to process? What sites or blog posts out there describe an adjusted or modified GTD process that surrounds such a lifestyle?

Thanks in advance for any help!

-Evan