When I switched to BBEdit, one of the things that annoyed me was that the documents drawer--the sidebar that lists all open files--appeared on the right instead of the left, with no apparent way to move it from one side to the other. (In older versions of BBEdit, there was a preference for this, but it was removed at some point.)
After some digging on the net, I found a hidden preference that would let me move the drawer to the left hand side of the window, and posted it on Mac OS X Hints... where I was promptly informed of a much simpler solution, which I'm sharing here today.
To move the drawer in BBEdit 9 from the right to the left side (or vice-versa), just Command-click on the Documents Drawer toggle button, located on the right side of the BBEdit toolbar. If you can't see the Documents Drawer toggle, open BBEDit's Preferences, and select Text Status Display in the left-hand column, then click Documents Drawer Toggle.
Once moved, the drawer will stay on the left side through relaunches; it will only move again if you move it. I think you should be able to set this preference using the Documents & Drawer section of BBEdit's preferences, but at least there's a relatively easy workaround (although it's not documented anywhere that I can find in either help or the user manual). Thanks to Mac OS X Hints commenter bhas for pointing out the easy solution.
This story, "Move BBEdit's Documents Drawer to the Other Side" was originally published by Macworld.