Taking some basic electronics: Netbook, GPS, camera, battery charger. Netbook is incredible -- a Samsung N120, sub 3 lbs yet very high function, a terrific Daily Deal purchase on eBay. GPS -- a Garmin eTrex Legend, designed for cycling -- seems an odd choice for someone who claims to have no fixed destination hence no need for location, but I have discovered that I want to keep a record of where I will have been. (How many tenses in that sentence?).
Camera will probably be Canon S3. Battery charger prevents leaving a trail of dead AA batteries along the way.