Start with the basic circle image making sure you still have the Circle layer as the active layer.

Deselect the selection by hitting Ctrl + D or going up to Selections | Select None. Go up to Image | Deformations | Skew and set the Horizontal to -36, the Vertical to 0 and then click OK.

Your Circle should now look like this:

To move this around to make a button or banner out it, we need to resize the canvas so we don't cut off the edges. Go up to Image | Canvas Size and set the New Width to 600 and leave the Height at 300 and have both the boxes for Center Image Horizontally and Center Image Vertically checked.

Your image should now look like this:

And now to rotate...Go up to Image | Rotate, set the Direction to Left, Degrees Free 45, make sure that All Layers is NOT checked and click OK.

Here's one I colorized and added text to. Use your imagination and see what you can come up with!