I've looked around quite a bit, and haven't found any discussion on the matter. In fact, when I check other WordPress templates, it seems like people are either manually inserting horizontal nav bars to insert cool • or | dividers between the links, or they're simply leaving the list with no dividers at all.
I want both! I want automatically generated menus (in or outside a widget), with cool dividers (without that extra one at the end!). I cannot for the life of me figure it out.