iMaker is an image splitting tool. If you have a single large interface image you can use iMaker to split the image up into a usable interface. It even generates the HTML code which should be used to "redraw" the interface in it's complete state.

iMaker Features
Generation of JPEG, PNG or GIF output files
Generation of HTML table to redraw the complete interface
Opens JPG, GIF or BMP interface files
Interface split up can be stored for later reuse
Includes 3 samples