I think I've finally sorted the GoPro home-made handlebar mount (the last one proved a little prone to shaking and drooping whilst riding on rough surfaces).
When I say 'home-made', I really mean I've combined about £100 worth of Manfrotto hardware I had lying around with a small eBay purchase. I might have doubled the weight of my cardboard bike, but it's solid as a rock and the footage looks uber-smooth.
I've also realised the camera is small enough to fit into all sorts of strange places, like the inside of the coffee grinder. Combined with its time lapse feature, you can take all sorts of weird pictures of yourself.
Which might be a good thing to save for a rainy, blipless day.