Any suggestions for getting between these cities. Either by land, sea, or air?
Take the train. See the timetables at www.bahn.de. Click on "Internat. Guests" for English. After you get summary timetables, click on "Show details for all" to see the connecting points.
Definately the train. I have done this trip and it is really lovely. The scenery is just great.
I agree...take the train. IMO, one of the most beautiful train rides in Europe. It's simple too, only one connection in La Spezia.