I just upgraded a bunch of sites to DNN7 and have a few pages that are meant to be "full screen".  The new DNN7 control bar gets in the way in these circumstances and I too find myself needing to hide the control panel in some cases.  

My solution was to add CSS to the page where I want to hide the control bar.  I know CSS was referenced as a non-ideal solution in the context of this thread, but I don't see why it's not ideal.  Either way, hopefully this response helps someone who considers a CSS fix "ideal" (like me!).

I was able to get the CSS to hide the Control Bar ONLY if you aren't in Edit mode.  So if you go into the page in View mode it will display full screen and hide the control bar.  However, if you enter Edit mode on a different page and click the checkbox to "Stay in Edit mode", going to the page with the different skin using my CSS hack would show the control bar because DNN is nice enough to add the "dnnEditState" class to the body element. This way, you have a way to get to module settings, add modules, etc.

The trick is making the CSS more specific than the default CSS included with DNN so your CSS takes precedence.

body #Form.showControlBar { margin-top: 0px !important; }
#ControlBar { display:none; }
div.#ControlBar_ControlPanel { height: 0px !important;}
body.dnnEditState #Form.showControlBar { margin-top: 53px !important; }
body.dnnEditState form #ControlBar { display:block; }
body.dnnEditState form div.#ControlBar_ControlPanel { height: 53px !important; }