2x telephoto adapter
 

Just wondering how well these work? Haven't tried one yet.

Check out the Tiffen tele adaptor in the 43mm thread size at Leo's Cameras. (Downtown Vancouver, Granville St.) They work fine, but steal LUX. ^_^

I use a Raynox 2020 2x teleconverter (http://raynox.co.jp/english/video/egpanasonicdv952.htm) with my MX300 for videoing wildlife. Its' OK, but you can only use it on full zoom - if you zoom out you get a periscope effect. The image is sharp enough in the centre of the image, but goes quite soft towards the edges. Also you can get noticable purple fringing to white point light sources on the periphery of the image (these shortcomings show on the duck image on the above web link).

I also use the Pana 1.4 x Teleconversion lens (VW-LT4314ME) which is noticably sharper, does not have the peripheral anomalies of the Raynox lens and can be used through the entire zoom range of the MX300. It's an altogther better lenses, except that it only magnifies 1.4 times, not quite enough for some wildlife shots with the MX300.