Listen to technical podcasts. There are tons of them out there depending on the technology you want to learn and it's one of the reason I love my iPhone. Podcasts can help you learn about new technologies and the discussion process usually gives a lot of insight into the techs specifically that a book has a harder time of capturing.
I am actually really suprised by how often I talk to other developers and many don't even understand the value in podcasts or in some cases what they even are.
It sounds like your commute doesn't involve you driving through so your hands are free to read a book, even doing some coding (get a laptop if you haven't got one already) and subscriber to many technical blogs with an RSS feed so that you can read them offline (tether a laptop if you can for even more flexibility to surf and learn on the go). If you did however have to drive, this is where podcasts would really be of use.
As for books, read Code Complete if you haven't already.