I have a laptop and bunch of 5 min segments throughout my day. I used to think this was simply too short a time to do 'anything'. Though with a little practice and a few minor behavioral changes (like unplugging) I have realized that I can get something done in each segment. So now I am reaching out to all you quick-draw-programmers out there for more tips that will let me get something done in the shortest time segment.
Here's an idea: when you have larger chunks of time, write some unit tests for functionality you plan to implement. Then, when you have a 5 minute increment, choose a test and write code to satisfy it. This way you aren't spending any of your 5 minutes deciding what to work on, you already did that and documented it in the form of unit tests.
And hey, you get TDD and test coverage for free. Bonus.