Do you want to turn one of the guides 90 degrees? Easy and simple.Catala - Castellano
This is the kind of thing you come along by mistake. I was trying to copy the contents of a layer in one of my Photoshop files (Alt + drag) and by mistake I pressed Alt and clicked on one of the guides I was using to align my image.
Magic!! The guide turned 90 degrees with the rotation point were I clicked.
I don´t know how useful this can actually be, I just thought I'd share.