This project shows how to use the kMenuItemAttrCustomDraw menu item attribute and the kEventMenuDrawItemContent Carbon Event to draw a custom menu item. It also shows how to draw the item using either QuickDraw or CoreGraphics.

It's for use under Mac OS X 10.1 or later. (If you only need to support Mac OS X 10.3 or later, you should investigate using HIMenuView instead.)

Download the project and source.