I recently came to discover that my iPad can tether to my iPhone Internet connection. This means that while I am on the red line to work I can use my iPad on the Internet to be productive. Suddenly work that I have been needing to do at home can be accomplished while I am in transit. I found a new block of useful time.
The trick to getting iPad and iPhone tethering to work well is to first have a mobile plan that supports it. The second is to go into your iPad settings where you will see your iPhone. You can click your iPhone and it will connect. Less than a minute later you should be online. The only downside to this is it will go through your iPhone battery quickly.
Processing my email and todo list are chores that keep things organized in my world. While not everyone puts in the time and effort to do this, it makes a big difference for me. So I usually spend time on the train doing that. It also gives me an opportunity to write or read. Now I can spend my time at my apartment doing more important or fun things.