This winter has brought particularly brutal headwinds. I flew from LAX-HNL in December and the flight took 1 hour longer than normal. This has been happening regularly (at least once or twice a week) on Hawaii flights this season. Additional comments can be found in the Alaska Airlines forum (their SEA/PDX-Hawaii flights on 737's have been routinely making fuel stops in OAK) and the US Airways forum (their new CLT-HNL flight has been frequently stopping in PHX or LAX).