These two plugs are quiet standard i've seen them in shops and on ebay, easy to find and cheap. Make sure that the "golden" plug fits strongly into the GH2 plug to make a reliable contact.

Take the interior part of the golden plug and the exterior part of the silver plug, bend the interior of the golden plug or just cut it off so it fits the the shape of the silver plug.

Fit the golden interior part into the exterior silver part of the plug, so that the little "minidisc" (red arrow) of the golden plug is outside, if not it doesn't make contact. Sorry - I just realized that the exterior angled silver plug has a plastic inside whith which you fix the cable. I forgot to put it into the photo. But obviously that helps a lot the stability of the plug.

Done!

The sound of this little jewel, built in the well renowned german/austrian AKG house, is superb - very natural and clean, voices sound warm. It has a particular strong directional characteristic/off-axis rejection and wide frequency range. It supports very strong signals as much as it picks up clearly sounds and voices coming from the distance. Reading the reviews you can see how versatil this microphone is http://www.proaudio.com/product_info.php?products_id=3480.

It is very small, 137mm x 9mm, size of a pencil, is very light, perfect for using on any small hybrid or DSLR cameras.

Talking to the AKG tecnicians in Austria, they had their doubts whether it would work with such a low (2.5V) "power supply" of the GH2. Normally it works with 9-52V. But: it did work (Thanks Mr. Amon for your advise).

Connection is: red to "tip" and "ring" and white and ground to "sleeve". Basically the same way as described in @balazers topic. You have to cut off the 48V phantom power plug previously.

The microphone shock mount on the photo, was custom built out of a stainless steel tube, with my local boat-welder in my Marina and a few rubber bands.

The lack of any existing 2.5mm stereo plug in an angled version (I only found crap), made me change the "interor" of an angled 3.5mm plug and substitute it with the interior part of a normal metal 2.5mm plug. Works fine. No need of annoying 3.5/2.5 adapters.

For my purposes this is a very satisfying setup. With the great picture quality of the GH2, using balazers stable cake settings (thanks @Vitaly and @balazer), now I finally found a very small high end on-camera microphone with a wonderful sound quality, no need of any further batteries or power supply, and the whole thing still keeps this small, flexible, moving character which I love to work with.

The AKG C747 is not cheap, the actual version MK II costs around 500€ or more, but the previous version, which is basically the same microphone (a part from a filter and a few other things), you can find it used for around approx 300€, add approx 30€ for the Windscreen.

Would love to hear your opinions about it.

EDIT: Cheap deal on AKG C747 on ebay: http://www.ebay.co.uk/itm/150918575896?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1558.l2649#ht_1249wt_1219