I also like the slightly faster lens of the Olympus over the slower T4. Sub-compact P&S cameras are a bit more prone to being too light thus sometimes producing blurry results due to camera shake.
Disposables are certainly better than nothing if your real camera craps out! One time I had a shutter jam early on during a Rainier climb and didn't get any pics above 10,000'
I completly agree about keeping a camera out of your coat in the cold. I read a few articles about condensation damage to lenses as well as cameras if one is not careful.
Anyone else play around with black & white film up high?
In the end, regardless of your system (be it disposable, P&S, APS, 35mm or larger) a little knowledge about composition goes a long way for picture.