Auto-hide the OS X menu bar system-wide

I wish to write a utility to auto-hide the menu bar, much like the dock. This would replicate the a OS X 10.4-only application "Menufela", but for Snow Leopard.

[[NSApplication sharedApplication]
     setPresentationOptions:   NSApplicationPre开发者_JAVA百科sentationAutoHideMenuBar
                             | NSApplicationPresentationAutoHideDock];

This code auto-hides the menu bar (and dock), but only in when the application is the frontmost window. How would I go about applying this behaviour system wide, regardless of what application is open?

The only thing I can think of is an InputManager, but I haven't written one before, thus I'm unsure if this is the correct way to go about it..

Also it seems InputManagers are limited as of Leopard/Snow Leopard - from this SO question:

it won't run them in a process owned by root or whell, nor in a process which has modified its uid. Most significantly, 10.5 won't load an Input Manager into a 64 bit process and has indicated that even 32 bit use is unsupported and will be removed in a future release.

I'm not concerned about the "will be removed in a future release" (it just has to work on Snow Leopard), and I don't think root-owned processes are an issue (all GUI applications should be running as the current), but presumably the code would have to be injected into many 64-bit applications (Finder/Safari/etc)

(I originally asked this on SuperUser, here, but as there was seemingly no existing utility to achieve this, it's more relevant to StackOverflow)

The kiosk API is probably your best bet for this, though I haven't used it in years and don't know if it's even supported anymore.

http://developer.apple.com/mac/library/technotes/tn2002/tn2062.html

I hacked together a small SIMBL plugin to hide the Menu Bar: http://github.com/Crazor/MenuBarHider It uses the SetSystemUIMode() Carbon call, which is not limited to 32bit apps.

I haven't used it on Snow Leopard myself, but the only way of injecting systemwide that even has a chance as far as I know is mach_star, and even that will be a bit tricky. Apple isn't making this easy these days, which is why a lot of the old hacks are failing to be updated either in a timely manner or at all.

This recent Cocoa With Love article has information on how to hide the menubar:

http://cocoawithlove.com/2009/08/animating-window-to-fullscreen-on-mac.html

However, using the CarbonAPI (SetSystemUIMode()) requires the app to be 32-bit and does not work outside the scope of the application.

Edit: and reading a bit further, it seems that this API doesn't do anything that -[NSApplication setPresentationOptions] can't do.