I needed a long remote shutter release for my E-P1. This is the details :

The first thing you need to know is the pins to release the shutter. The pins are pointed out in green. From some postings on the internet, they refer to the top pin as "pin 11", the bottom pins from left to right is "pin 4" and "pin 3" respectively.

pin 11 + pin 3 = half press i.e. focus.
pin 11 + pin 3 + pin 4 = full press i.e. shutter release.

You can hard wire pin 4+11 together if you never want to pre-focus. This means when pin 3 is added, it will focus then shutter.

(After further investigation, it appears pin 3 & 9 can be used interchangeably, maybe it's just the ground?)

So the question is, where do you get such a plug. The answer is... that video out cable you never use. Take the video out cable and cut the plastic cover off the plug.

Once you remove the cover you will be left with a plug which you can pull off the cable. There's a bunch of metal contacts sticking out. Here you have 2 choices, yank them all out, or yank them all out except pins 3/4/11. If one of those pins came out with the cable, you'll have to put one of the other pins into the spot. You now need to solder a wire to the contacts, so either solder the wire to the contacts sitting in the plug, or solder a wire to the pins and then put them into 3/4/11 of the plug.

This is a picture of me testing the pins... I just stuck the plug into the camera and hot wired the pins to test.

For the wire, I used a telephone cable. It's cheap and has 4 wires, I only really needed 3 of the wires.

Once the plug is soldered to the wire, just blob a ton of hot melt glue over it to make it a solid piece.

On the other side, I bought 2 press button switches. One switch activates the focus, the other activates the shutter. The plan is to tape the two buttons together so pressing it will cause it to focus and shutter.

The picture is the finished result. 2 metres long and works like a charm.