Full-screen apps in the newest iteration of Mac OS X (Lion) are very cool things when viewed from the simplest use case scenarios.  Especially if you’re using a trackpad to interface with your computer.  Everything else gets out of the way, and you can concentrate on that one app while you work.  Excellent.

Wait. Hold on a second.

Do you have more than one display attached to your computer?  Don’t bother using full screen apps.  You’ll get that app full-screen alright, but at the expense of the ability to use any of your other screens.  That’s right: the app will zoom full screen on your primary display, while all others will display a lovely gray linen background (and do nothing else) until you come back out of full screen. Useless. Dare I say: “fail”? Yes.

Fail.

Why on earth can I no longer use my other screens for anything?

Another area where full-screen apps are less than bright and shiny is in how they deal with notifications from other (now background) applications.  In short, they don’t.  If you are, for instance, browsing in Safari full-screen, and also have Mail running full-screen in the background, you have no really effective way of being notified when new messages are received by Mail.  There’s no Dock visible, and therefore no badge on the Mail app’s dock icon to inform you there are now messages waiting.  Instead, you have to continually go switch to Mail to see.

Fail.

Yes, yes, I know you could hook up GrowlMail and let it notify you via Growl.  The point is that something like this needs to be baked into the OS itself if you’re going to suddenly take away all of the existing options for gaining the user’s attention for something like an incoming mail message.  Speaking of which, I vote for directly embedding Growl into Mac OS X, and directly embedding Growl notifications into all of the built-in apps.  Probably not feasible due to licensing restrictions, I know.  But it sure would be cool.

Do these two warts keep me from using full screen apps? No. At least not on my laptop, where I’m typically limited to one display.  Swiping between the full-screened apps is very convenient and cool.  I use it there.  On my desktop workstation, however, where I have dual screens, yes this absolutely makes me not use full screen apps at all.

I’d really like it if full-screening an app zoomed that app to the display it happened to currently be on, while leaving all of the other displays on the system alone.  I’d love to have the ability to zoom an app on each attached display.  Very useful.  I realize that this capability would require some thought on how to most effectively use the swipe gestures to switch between zoomed apps.  Perhaps the swipe could switch between apps that are zoomed on the display where the cursor currently resides?  Dunno.  Anything is better, however, than essentially taking away all of my other screens when I switch an app to full screen.  That’s just dumb.