Scan lines for older systems?

Does any company out there sell a device that will add scan lines to an Xbox,PS2,or Gamecube?

The reason I'm asking is because these three system look terrible on an HDTV.

GameCube : I can play gamecube games through the Wii, and they look pretty good on the HDTV. (takes care of gamecube)

Xbox : only a handfull of games are backward compatible and updates have stopped a long time ago.

PS2 : Unless you were lucky to buy one of the first ps3's released, there is no backward compatability.

I want to keep playing the xbox and ps2 games, but they just look ugly on HDTV.