Is there a way to auto-hide the OS X menu bar, like is possible with the Dock?
There was an application "Menufela" that did this for Tiger, but I'm not aware of anything similar for Leopard/Snow Leopard..
I'm almost certain this is (programatically) doable, because in full-screen applications the menu bar is hidden, and reappears when you mouse the mouse is at the top of the screen..
Edit: With the help of Steve Folly's answer, the following code:
[[NSApplication sharedApplication] setPresentationOptions: NSApplicationPresentationAutoHideMenuBar | NSApplicationPresentationAutoHideDock];
..will auto-hide the menubar (and the dock, as mandated by the API), but only for the current application:
When controlling or disabling features of Mac OS X system using SetSystemUIMode the requested behaviors are only in effect while the process which called SetSystemUIMode is frontmost
..close, but not quite there