Hacking and internet connectivity

I just got off a plane between Dubai and Seattle and although it was a very long flight it turned out to be one of the more productive ones I'd taken in a while. Generally when I get on flights I start to code a little and realise that without any reference material I quickly lose motivation. So this time before I left Dubai I got some protobuf libraries and basic reference docs describing some encoding schemes etc. and I ended up getting much more done that I normally do at home. Instead of browsing around and checking HN, I took quick breaks to read a chapter or two of a book and then opened the laptop again without immediately procrastinating. Any suggestions on how others get around getting sidetracked when working on personal projects?