I keep track using a combination of technology and friends. My friends and I share a Backpack page and find it to be super helpful. Mostly we make lists of the things we want to get accomplished before the Monday of the following week.
For example, my list for this week looks like this:
Abel - Feb 2
--[Project Name]: Finish implementing design changes for game room
--[Project Name]: Implement code to prevent multiple submissions
The good thing about this system is that we can all see the what we've promised ourselves. When we slip on getting things done, our penalty is to buy a round of beer the next time we see each other. We also have reward system too. If you bang out a lot of things in 7 days, you can pull beers off your tally.
Backpack is also great because it has a pages where you can jot down ideas as well. It won't fit on a thumb drive, but at least you can access it anywhere you have an internet connection.