ObjectDock supports creating of themes now. We recommend using this format for submitting things to the ObjectDock library. To use it, simply get your dock just how you want it, and then go to file->save as an .odtheme. It will save backgrounds and dock icons and more.
Make sure you have permission for any dock items you do submit though. But for those who have created an entire set of dock items and want to submit that, use the theme format. It takes away the tedium of having to manually set up the dock items later on.