Everyone loves a mystery & the conspiracy theories about this started a few days after she disappeared. I think it's more than likely that they simply got lost, ran out of fuel & ditched in the sea. The Pacific Ocean is a very large expanse of water & Howland Island is a tiny speck on the map. http://www.infoplease.com/spot/desertisland9.html

This is very similar in some respects to Earhart's British counterpart Amy Johnson. Although she was flying solo over land she was way off course & ended up over the Thames Estuary which is a much smaller area of water than the Pacific Ocean. She was seen parachuting into the water but was unfortunately dragged under the rescue ship's stern. Neither Amy Johnson nor her aircraft were ever seen again.

There are all sorts of exotic theories about her disappearance but it's most likely that she simply got lost in bad conditions & ran out of fuel. Maybe her pride in her reputation wouldn't let her admit defeat & turn back where a less famous person wouldn't have even considered flying in those conditions. Excellent report on this here. http://www.rafsaa.org/johnson.htm

PS. Another example is the disappearance of Major Glenn Miller. These stories will continue as it's unlikely the truth will ever be discovered.