The Caption This! Curtains
Caption This! featured graphics of red curtains a la a movie theater framing the current grab. Any sort of (usually) red curtain might be capped with some reference to the CT! curtains, often with a suggestion that they are taking over.
Examples
From http://diabah.farvista.net/hall15.htm
!["...our very special guest, the Caption This! Curtain. Yaaaaaaay!"](/wiki/images/a/ac/CT_Curtains_1.jpg)
From
http://slidersweb.net/blinker/capped/seer/
![Don't look now, but the CT! curtain is taking over.](/wiki/images/b/bd/Curtaintakingover.jpg)