Multiple Monitors

I work for a local government and want our Engineering Department to look into getting dual monitors for their mapping programs. I know there are video cards that support dual monitors, as well as the option for buying two cards. But I also heard there is a Y-cable out there that plugs one end into the video card and the other ends into different monitors. Is this true? I have search everywhere I can think of and have found nothing like this. We are using WinXP Pro.

Thank you for your help.