But there is the little problem of Canada...in between us and the lower 48! No problem traveling between Alaska and Hawaii, or AK and the lower 48 AS LONG AS YOU DONT STOPOVER in Canada...which usually you would not if you flew... but if you drive (or in some cases, boat), you will need to show a passport, passport card or Nexus card at the Port of Entry. As far as I know, a birth certificate and a license are no longer acceptable.
http://gocanada.about.com/od/canadatraveloverview/qt/uscitizenborder.htm
"Bottom line: Since June 2009, everyone from every country arriving in Canada by air, land and sea has needed a passport or equivalent travel document. (Some exceptions apply to children's passport requirements). Besides an up-to-date passport, visitors may instead have an equivalent travel document, such as a NEXUS Card."