A very important question: how are you traveling? If you're using mass transit, or if someone else is driving, then you have many options. You can read technical material, you can read for enjoyment, you can talk with other riders for professional or personal interests, you can do productive work on a laptop, or you can sleep. If you're driving, then your choices are more limited. Conversation would be the first choice, but it depends on your co-riders (if any). If you're solo or have boring co-riders, then I strongly recommend books on tape. Most local libraries in the us have many that you can check out; I don't know about other countries. You can find books on tape that advance your career, or books on tape that keep you entertained. Either way, the time spent listening shouldn't be a total loss. [ July 04, 2007: Message edited by: Jim Yingst ]
I commute more than an hour each way by train, and I read and/or listen to radio, music or blogs (ScienceFriday.com audio blogs are very good). If I get a comfortable seat and feel like it, I can catch up on mails, work, process photos etc, watch some tutorials, movies etc etc etc. Or just select some calm music, and sleep. I am thinking of taking mobile broadband so that I can be online as well!
It takes me 1.5h. In the morning, I usually can't do better than listening to music, or news with my iPod. It's so crowded that I usually can't find space to read. In the evening, I usually read something.
1hr each way for me and I use the time to listen to podcasts on topics that interest me. Music is also good as it puts you in a better mood before the working day begins and helps you unwind when it is over.
Pounding at a thick stone wall won't move it, sometimes, you need to step back to see the way around.
I thought the topic was "using time travel effectively" and I was really interested! I used to drive 20 minutes and liked my time with public radio going both ways. Now I drive about 5 and have to get my radio over the net.
A good question is never answered. It is not a bolt to be tightened into place but a seed to be planted and to bear more seed toward the hope of greening the landscape of the idea. John Ciardi