ToggleGameMode [TGM] is the easiest way for your players to change between creative and survival gamemodes on your server. Players will have access to toggle there gamemodes by default. Download: http://www.gamefront.com/files/21601978/TGM.jar
Let's ignore the elephant in the room for 2 seconds and point out something else: You forgot the download link.
You don't follow the plugin submission guidelines, and to be honest, this has been done a thousand times before. I'm glad you're developing plugins and such, but not every plugin has to be released.
And why do you want to use Vault in the future? Bukkit has it own PermissionsAPI which is good enough for this. And like everyone else said - follow the guidelines And there are tons of GM Switcher plugins out there....