Permanently hide Finder sidebar

Open the root folder of the drive (the icon of the drive on the desktop). Press Command+Option+T. You should be left with just a window of items and a bar at the top.

To get the number of items and available drive space to show, go to the Finder menu and choose Show Status Bar. You only have to do this once. All folders will now display this info.

To get all new folders to be created this way, have the folder set the way you want it to appear, then press Command+J. Change something, anything, so the Use as Defaults button is active. Click it. If you didn't actually want what you changed, change it back and press the button again. Close the options palette.

All new folders will be created as you set it, with the exception of the desktop, which will always open new folders with the sidebar when created there.

When I press Command + Option + S to hide the sidebar, and I open a new Finder window, the sidebar is still hidden. It doesn't come back in new windows until I choose to unhide it. As far as I know however, there is no way to permanently remove it. You can only hide it, just like you can hide the sidebar in Safari.

FWIW, Views are set for each folder. So if you hide the Sidebar for example for the Documents and the Pictures folders, the sidebar will remain closed for those folders until you change them. Their settings has no effect on other folders. There is no way to globally set the Sidebar that I'm aware of.

Edit: Although Kurt's reply seems workable.