Two monitors on it's Side While One Right Side Up? Weird!

Okay so this is my question and its kind of weird. As it stands now i have a triple monitor set up. I have a 24" LCD in the middle and 20" LED widescreens on either side. I would like to turn the 20" on their sides so they stand tall but yet still beside the 24" which will still be right side up.

How could i go about doing this? Not the mechanical aspect i'll design someway to mount them i mean the software and OS aspect where i can turn the display on just those 2 displays without having the mouse go screwy when i move the cursor to either side. Any help? Thanks

 

can you make it any clearer? some visual aids perhaps. really confused, which monitor goes here and there.