I thought this was a post about OTC meds. 
I assume you mean tabbed docks? You should be able to grab at the right end and stretch the dock to hold more icons? I don't use OD much, but I will test my theory and get back atcha!!
Edit: After trying what I just said, you should be able to stretch the dock from either end, allowing for more icons. Adjusting icon size in the settings may help also.