I like to use a freebie drawstring bag from the Cycle the Wave ride on long rides. I probably carry too much stuff, and I'm getting better about that, but the wide variations in temp/precip throughout the day make it a necessity in my book. It is light and comfortable I must say, so I can't see a reason not to wear it. The bag also makes me recognizable on various organized rides and such. Not sure if that's a good thing or a bad thing. If I ever do something stupid/jerky on on one of those rides I'll have to look for a new bag...
Rodriguez Adventure
Bacchetta Bellandare
HPV Gekko fx
Custom Rodriguez Tandem
2009 Specialized Tricross
2012 Trek Mamba