Making horizontal lists out of ULs, LIs etc is currently a hack.
You have to change from a list-item display type to an inline display type. Because of this "hack", you cannot have horizontal lists with bullets (images or other style bullets). Or rather, you can have a bullet but that's another hack (background-image, content injection).
So, can I propose a horizontal-list-item display type?
I obviously have not thought out the full consequences of this - for example, how would you handle nested lists with horizontal-list-item? Do you use a vertical indent for nest lists?
I'm just a simple web dev who is struggling to produce simple and elegant HTML+CSS without hacks.