I too would be interested in this. As most of the canyons here in CO, your either in 1st or 2nd gear and the bike heats up pretty quickly.
Last summer I looked for a lower temp thermostat, that way the radiator starts flowing earlier, but had no luck. I've debated about Water Wetter, but I was told that it really doesn't work to efficient in city driving and of course my bike is my commuter as well.
Any input would be awesome around this subject.