Use Zappos as much as possible. No charge for shipping either direction!
Also REI has more available online than at their stores, and you can have them sent to their stores for free and try them on while you are there.
I recently went to the drawing board on trail runners. The new Golite offerings got me fired up to really focus on the best shoe for me.
I ordered Golite's, Inov-8, and Montrails based on the reviews at this site. It became readily apparent that Montrail's are never going to be an option for me. I ordered a wide and they were still very tight! The Golite's are probably too far in between sizes (without offering half sizes) to accomodate those like me that have feet that are maybe 7 to 10% different in size. The Inov-8 fit very comfortably, if a little snug, but I did not feel that the Flyrock's composition was substantial enough for those trails that I frequent with sharp granite stair like climbs.
The bottom line seems to be that all of the things that are touted by user reviews….mainly features and functions, it tends to bypass fit…which above all else is the essential first hurdle to making the right purchase.
It would be GREAT if this site or another could not only explain how to self examine your foot size/volume, but also tie those brands which are best for your physic into a nice little package. That way, a guy like me knows right off the bat, that Montrail will never reside in my gear box.