You had to wait until I started working from home to tell me this, didn't you? ;-)

Maybe it's a tablet PC bit that got left in normal XP, kind of like those table-style games consoles that flipped over when the other player's turn came up: you can sit on opposite sides of the tablet and change orientation easily.

Either that or it's for people who mount their flat screens on the wall upside down.

Tablets. Of course. Thank you.

This isn't actually an XP thing. A lot of graphics card drivers have orientation controls that allow for different monitor types. They are usually controlled by the CTRL+ALT+arrow key combination. In UK systems ALT Gr can be used instead of CTRL+ALT (although you cannot do ALT Gr+Del for some reason) Some differ slightly and have double-pressed combinations and stuff. Pretty much all onboard graphics cards on HP/Compaq machines have this. (On board ATI and Intel chips)

The main use for this, other than tablet PCs, is that a large number of TFT monitors can pivot at least 90 degrees for a portrait display.

You know everything, you do.

The 90-degree pivot isn't at all baffling -- I could see why people might want that. It was the 180 that I couldn't figure out.

There is a sort-of logical reason for that too. Windows 2000 and later can support up to 10 monitors (you obviously need lots of ports/slots) and say you were putting together some sort of video wall thingy you may want some cards to output upside down to avoid the thick part of the monitor being at the inside edge. I have seen twin monitors rotated at 90 and 270 together for this reason.

This is soooo cool. Thank you...