Interlaken to Cinque Terre

Jessica, the only reasonable way is by train. Your routing will be Interlake/Spiez/Milan/CT. On some runs, there may be additional train changes at Brig, Dommodosola and Genoa. No way of telling what the run will look like until you reveal travel dates. In the meantime, you can look at the German train website www.bahn.de to see the runs. Expect a train journey of 7-8hrs and 3-4 train changes. No airports reasonably near either location.

I just did this exact route a few weeks ago. This is how we did it. 7:30am from Interlaken to CT via Milan. Arrived in Milan around 10:30am. Got out and went to see the Duomo and Galleria. Easy to store bags and ride the metro there. Back on the train around 2pm and arrived in CT around 5pm via Genoa. It is a very scenic train ride, especially the portion from Interlaken to Milan. It goes quicker than you think it would and with the stop over in Milan did not seem long at all. Definately cheaper and less hassle than a $1,000 flight. We had a rail pass so needed a reservation for the Italy portion, not the Switzerland portion.

Jessica, As the others have mentioned, travel by train on that route is by far the best and most cost effective option. I've travelled that route several times but prefer not to make any "stopovers" along the way as the trip is long enough as it is (basically a full travel day). In the same situation I'd use a departure from Interlaken Ost at 07:29, arriving Monterosso at 15:02 (time 7H:33M, 2 changes at Spiez and Milano Centrale, compulsory reservations on last two legs). There's also a departure at 08:00 with three changes, but half an hour shorter travel time. I used Monterosso as the destination, since you didn't specify which of the five towns you'd be staying in. It's only a few minutes from there to any of the towns so the travel time won't be much different. Bus is NOT a reasonable choice on that route! Happy travels!