Can you use the video part of the camera? I don't know how long you can record for, but if you just set it up as if you were going to video a party for example, and then press start when the person answers, you'll get a video of your sideboard, but a recording of the person's voice?
Thanks both. I had a google and found a few apps, but it looks like you have to register to a server etc. anyway, I've done the phone call I would have needed it for so it's all a bit surplus now.