For reflections a CPL is a must have. All of the saturation/color effects can be reproduced in post. Many brands offer wide angle cpl filters with a much thinner ring to reduce vignetting.
Drex, it's 90 degrees for maximum effectiveness, not 45. :thumbup:
And I also highly recommend the German B&W filter. It's expensive, but is sharp, is coated to prevent glare/flare/whatever, and won't fall apart like the piece of crap that I bought to replace it when I smashed it against a rock. I got the slim one to prevent vignetting, but did not get vignetting on the the normal one I bought as a replacement and really loved that I could put my lens cap on without taking the filter off. Before my next vacation, I'll be buying another B&W, but a non-slim. It'll pretty much live on my 10-22.