Years ago (thinking back to an Escort I once drove that had this "feature") I routed power to the washer pump directly to a separate switch. This allows me to soak the windshield before turning on the wipers so I'm not dragging the dry wipers across the dirt/salt/etc for the first pass. As an added benefit, the pump now works better because the new wiring provides better voltage. :D
Also, this summer I'll be installing an XJ washer pump with the dual pumps (one for the XJ rear window). I'll wire up the pump to another switch and somehow route the piping up to the windshield so I can quickly double the amount of water hitting the glass. It's not like I think I need it for lots of mud, but it's just another one of those ideas I had that I feel the need to bring to fruition, just for the hell of it. :D