How to move all iPhoto video files to an external disk or a NAS?

Question

The main harddrive of my MacBook Pro is filling up. So I need to move some files to an external medium.

I use iPhoto to import my photos and (HD) videos from my digital camera. I want to keep all my images in iPhoto, but I'd like to move the space consuming videos to another medium.

Is there simple, possibly automated way to move all the video files (.mov) that are in my iPhoto library to an external folder (NAS or disk)?