iSwitcher is a theme / keyboad swapping iPhone application.

Changes:

iSwitcher can now install Keyboard layouts just like icon themes. v1.45 includes four keyboards and 4 themes, Changes to iSwitcher also include new theme aware pop-up dialogs. Depending on which theme (first time backup, restore, etc) the pop-up provides the user with appropriate information.

http://code.google.com/p/iswitcher/