OK, I just got a simple genereic 52mm clip on lens cover from ebay, and while it fits, it's a bit of a push to get it on. So far it says on, but looks wise (to me anyway) it's not that great. It doesn't have a tether string either, it just stays on by being ever so slightly smaller than the lens. Been using it for a day or two now, so still not used to it. At least it's protecting the lens. And those that have looked at it didn't say anything about it looking out of place.
Only cost me £1.50, so can't be bad to that.