Three ways to hide the Facebook sidebar with userscripts
If you don't like the new Facebook "Highlights" sidebar, and you've been dying to get rid of "People You May Know," then you should definitely consider installing a userscript that will hide those elements for you. The appropriately-named "Hide Facebook Sidebar" script does the trick quite nicely, while leaving your events and friends' birthdays alone. There's also "Hide Highlights Sidebar," which hides highlights, but doesn't get rid of the "People You May Know" box. I personally find that particular recommendation feature useless, as it always suggests people I'm intentionally not friends with on Facebook, and there's no way to filter them out. If you like it, though, then you should pick this script instead of Hide Facebook Sidebar.
If you'd rather get rid of both the left and the right sidebars, and expand the main feed to fill the space, you want "New Facebook - Remove Highlights and left filters." It's called New Facebook, but it actually makes the layout look a lot more like the old Facebook. All three of these scripts can be loaded into Greasemonkey (or your browser's equivalent) or Stylish, which is a Greasemonkey-like extension just for reskinning and making cosmetic fixes to websites.
