Problem
In a previous [one-liner] post I mentioned a quick way to get rid of Google’s new Left Sidebar. Here’s a screenshot from that post of the Google sidebar.

Google Left Sidebar
Well as of May 2010 it appears that the Google sidebar is back, and my hack of just deleting the google.com cookies no longer seems to permanently get rid of the sidebar. So now it’s time to bring out a bigger stick … greasemonkey.
Solution
If you haven’t heard of greasemonkey, it’s a plugin to Firefox that allows you to control elements of a page that you are viewing, essentially overriding the design of a given page. You can do things like get rid of sidebars, add your own buttons, etc. I’m not going to get into everything it can do, we’re only interested in getting rid of Google’s sidebar, and with greasemonkey installed it becomes a simple task.
First click this link: greasemonkey plugin to Firefox, and click on the “Add to Firefox” button on that page. Restart Firefox to activate the greasemonkey plugin. Next you’ll want to make use of a greasemonkey “script” that is freely available over on userscripts.org.
NOTE: The userscripts.org website allows users to share useful greasemonkey scripts.
The greasemonkey script you’re looking for is called Toggle Google SideBar. Each “script” on the userscripts.org website has a big install button on their respective pages, so just click that button to install it. Once you’ve done that you’re done.
Now Google search results pages will look like this with the sidebar visible:

Google sidebar open
…and like this when the sidebar is hidden:

Google sidebar closed
Notice the big [+]? This allows you to toggle the Google sidebar if you want to see it.
NOTE: For further details regarding my one-liner blog posts, check out my one-liner style guide primer.