marioguzman, 
Sheets!
Sheets in Mac OS X had such a lovely animation presentation.
They'd come out from a "slit" between the titlebar and the toolbar. You can even see the slit. It was so neat.
And of course the "Slit" would go away when the sheet would retract as you'd dismiss it.
The often reminded me of a page coming out from a printer (much faster of course). I miss the playfulness of Mac. :(