G1 X add-on lenses
I did a post a while ago regarding a 1.8x Siocore Teleconverter.
You can buy it here:
Siocore also produces/sells a wide angle converter:
Sorry, all just in German, but I assume they are not producing it themselves and are just re-sellers.
There is also a 2x Teleconverter and a 0.7x wide angel, but they mark them as "standard", which means lower optical quality.
I have been using the 1.8x Teleconverter now for a couple of month and are quite happy with it (please also see my comment "This is why I got the G1X and the tele converter" http://forums.dpreview.com/forums/post/42624240), but I have realized that it has a little vignetting which I did not see before. Anyway, you can either get rid of it in PP or by one step of digital zoom when you take the picture (similar to the Raynox wide angle).
One thing that I have learned is that having so much weight on the camera makes it much more difficult to hold it still so not to blur the picture. Was just yesterday in the mountains again and was trying to get a Chamoise. I ran up a steep slope to get closer and was panting away by the time I took the pics - several just blurred... ..should have used faster shutter speed I guess...
Nevertheless, I find the combination with the G1X quite a good travel and trekking combination. For city tours I would only bring the camera in a very small bad and on my hikes - especially when I am "hunting" for specific animals - I would bring both.