2011 Jayco 19H quick mods -- so far...
-- Master Switch and Electric Tongue Jack
-- Digital Thermometer / Hygrometer with outdoor probe
-- Screen-door grab-bar
-- Paper towel holder
-- Kill A Watt (AC Line Monitor)
-- Cigarette Lighter Inverter (watch TV while dry camping)
-- Dollar Store mini storage crates
-- 7-Way plug receiver with marker light jumper installed (lets you turn on your marker lights for night lighting by simply plugging in your trailer's tongue cable)
-- Shelves in what was the wardrobe for added storage
-- Towel hooks on bathroom door
-- Leveling bubble (x2)
Those are all the quick mods I've made so far -- plenty more to come!