For a project I’m working on, I wanted to take the sidebar in Twenty Ten and move it to the left side instead of the default. I played with it for a while and received some help from my colleague Ian Stewart, who kindly pointed out that I’d typo’d a CSS comment. (That wasn’t completely embarrassing.)
Turned out that at one point I’d had it and didn’t know it. Thanks again, Ian.
To post for my own recall and for anyone who might be looking to do it, here’s what to add to your WordPress.com Custom CSS if you’d like a left sidebar:
/* LAYOUT: Two columns-reversed
DESCRIPTION: Two-column fixed layout with one sidebar LEFT of content */
#container {
float:right;
width:100%;
margin:0 0 0 -240px;
padding:1em 0;
}
#content {
margin:0 20px 0 280px;
}
#primary,#secondary {
float:left;
overflow:hidden;
width:220px;
}
Ryan Markel 
Thank you… that was very helpful. Was trying to flip the sidebar and that did the trick. Cheers.
How about a quickie on adding a SECOND sidebar to Twenty-Ten – I’ve tried everything I can think of with zero success… I’m by no means a WP Wizard, however, so I’m guessin’ you’ve probably got a quick trick…
I haven’t looked into this, but it would be a decent bit more complicated—you’d be looking at moving one of the footer sidebars up to the main content area, since those are the only remaining sidebars to move.
This article describes how to make a 3 column twenty ten layout using some absolute positioning with the primary sidebar on the left and secondary sidebar on the right:
http://zeaks.org/wordpress-2/twenty-ten-child-theme-how-to
vali
Months ago after much trial and error I figured out how to swap the sidebar to the left in one of the older versions themes, but it’s been ages and I want to use this theme. So.. this is probably a noob question, but where do I insert that code? In styles.css? Which line?
Thanks =)
Ah.. nevermind, I didn’t know about child themes yet. Thanks, perfect code. =)
Hi Ryan,
Thanks for the info, i have tried this on my site, but any widgets i have added to the column appear down at the bottom of the page, any suggestions.
Thanks
Got it working, had to change this,
#secondary {
clear: right; } To
#secondary {
clear: left; }
Thanks,
Ron
Thanks very much for this, I am just getting to grips with wordpress and cSS and really grateful for guys like you who generously share their knowledge. Good Karma will try and pass it on.
Thanks for posting this. I haven’t had to do this trick yet in 3.x, so thanks for a simple answer and code. Now I’ll understand it from example.
Muchas gracias por el tip 😉