Does your bike have a mid-fork mount for the attachment of panniers? If so, you can install one of the aforementioned mounts or make your own. I have constructed several mounts out of PVC pipe for a total cost of about $1 each, using small PVC pipe and connectors that I bought at the hardware store. Here is a photo of my touring bike with the mount and a light attached to the front fork. Most of the time, I connect the mount to left chain stay and use a taillight on it while commuting.