One of my pet peeves is seeing text files (usually development related CSS or Ruby) with executable permissions in Finder which override any default icon and show a shell script icon.
Not only is this just annoying, it also may be security risk if you have a lot of files that can be arbitrarily executed when they shouldn't.
I used to do this in the Terminal manually when I encountered it but I've since turned this into an OS X Service.
Download and install the workflow into
~/Library/Services/ and you can now right-click on files, go to Services and remove the executable permission.