overscan compensation?

[IndieRockSteve]

My parents have a machine in the kitchen connected to an older Sharp Aquos that has PC and HDMI input but has no way to "defeat" overscan, so theres 5% of each edge hidden off the screen. My dad is looking to get a new LCD tv to replace it, but until then, does anyone know of a way to compensate for this 5% hidden area in displaying the desktop when using the HDMI output?

They have updated to 8.10 and are running KDE so if theres a way to do it in the nvidia drivers or with KDE4 that would be great.

Thanks!!