I commuted 27 miles (straight line) via commuter rail and it took me 1.5 hours each way. Rent was free (I lived at my parents) but it was tough. I was surprised by how long it took, and by the number of service interruptions that made the trip even longer!
I live 1.4 miles from home, and walking to and from work is one of the best choices I ever made for my physical and mental well-being. If you don't walk to work and can, I highly recommend trying it.
I plan on fixing up my bike over the winter. I walked this morning and it does take a while. It also feels rather dangerous given all the construction going on around here.
I am now happily working 1.2 miles from home.