Just a word of warning.
I just spend two hours finding out why my sidebar had gone.
I moved sidebar items around, I tried other themes, searched the forums, got worried about the smiley face, ...
I finally found the cause when, with a different theme, the sidebar reappeared, but at the bottom and with the first header incorrectly formatted. I dug into the source, for no reason tried to match <div>s and </div>s, and then it hit me:
I use <div align="center"> en </div> a lot to center pictures. Maybe I had forgotten to close a <div> tag.
Indeed, I quickly found the post with the missing tag, added it, and problem fixed.
Oh so stupid of me.
A formatter toolbar would be neat. I turned off the available one months ago because of bugs in alignment.