Small byproduct of another plugin development:
Generic plugin wich allows you to take screenshots of the first aviable viewport.
(Unfortunately it also takes panels in front of the viewport into account)

Version 2 has been upgraded to support win7 windows management and also includes a paste image
function wich will create a clipboard image inside the image editor.

 
Camera view export from VPR

If the viewport is a camera view, it will use its own boundaries.
( ideal for front projection mate painting)

testet with 9.3 and above.