I have a mini Martin guitar that I brought to the BVI last year. Even though it would have fit into the overhead bin of the Seaborne flight to Beef island, there was NO WAY that I could bring it into the cabin; it had to go back with the suitcases. I wasn't impressed.
That said, I was able to safely get the guitar home, but had to guard it everytime it went into overhead bins on the larger planes. People would happily jam their oversized carryons into the guitar if I were not there to stop them.
One other option is to bring an electric guitar with bolt-on neck and just separate the neck from the body for transport. A Fender miniStrat can be purchased for about $100; plays well and is nearly indestructable.