Here's a brand new one on me.

I just hit the right arrow on my keyboard and my monitor display went sideways... with the top of the page on the right.

Hit the left arrow and the top goes to the left.

Hit the up arrow and it goes back to normal.

What the heck? Is there a key combination that any of you know of that I can hit that will disable this?

I can only imagine I bumped something that turned it on - since I've had this keyboard for about a year now and never run into it before...

Thanks!

Well I know when you hold Ctrl and hit one your screen will turn maybe your Ctrl button is stuck or brocken other than that not a clue

Yes, I found that. It's supposed to work only with control>alt>arrow:
Stupid Windows Features - Monitor Display Turns Sideways or Upside Down « //engtech (http://engtech.wordpress.com/2006/08/01/stupid-windows-features-monitor-display-turns-sideways-or-upside-down/)

... but mine is stuck doing it only by hitting the arrow! I'll have to do some more rooting around. This stinks! :o

... ok, I fixed it by hitting control>alt>up...

The article is right: Stupid Windows Feature.

I think your keyboard ctrl and alt keys might have been stuck, and pressing ctrl and alt would release them again.

Happens to me all the time when I mash the buttons playing games, hitting the key again solves it :)