I am syncing my podcasts onto my mobile. I have found the perfect software MP3-player. The final step in my quest to make a good device for podcast listening out of my Nokia 6630. I am now modifying my Nokia Handsfree set to accept standard headphones. All I have to do is to open the little box containing the mic and mount a standard minijack connector.
By doing it that way I will keep both the mic and the button that lets you answer calls.
Note
All the pictures in this guide can be clicked to give you a closer look. And, for readers in countries with stupid legal systems I will have to mention that I do not take any responsibility for you destroying your new hansdfee while trying to apply what I have described here. That said, if you have ever laid your hands on a soldering iron, this is as easy as drinking a good dry martini.
Ericsson
This guide was inspired by this post in the HowardForums. If you have an Ericsson headset that post will help you out.
Let’s start

Use a small screwdriver to open the cover. On my headset it was tightened with a small amount of glue. It was no problem to carefully open it without destroying it.

Open it carefully. You will clearly see the mic and the switch. The interesting stuff is on the back of the board. Flip it back carefully from the top.

Now you can see where the headphones are connected. The four cables are connected to points clearly marked: L+, L-, R+ and R-.

Pick up your soldering iron and remove the old headphones.

I used an extension cable for headsets that also featured a volume control with a small clip so that I can clip the device onto my jacket. This will let the mic be placed in a useful position as well. The pin layout for a minijack is: tip=left, ring=right, sleve=ground. You can of course use any female minijack. Just make sure you know what cables is left, right and ground.

I made a hole in the plastic to be able to insert the new cable. Solder the cable connected to the tip contact point to the place on the board marked L+, the cable connected to the ring to R+ and the ground cable to one of the negative connections, left or right. Here you can see that I have used L+, R+ and only L- for the ground connection.

Depending on what kind of cable there is on your new connection you might want to throw in a drop of glue at the spot where it leaves the box. You want it to sit tight so this baby will last through all the extreme sports you do while listening to the Engadget podcast on your mobile.. You might also want to use some drops of glue on the case itself.
It will clip nicely back together, but you know – that 360 mute grab on your new pair of skis might put some strain on your equipment…

Now I can connect my Creative Travelsound to transform my Nokia into a ghettoblaster. I can connect my Sony noise cancelling earbuds and I can even borrow my wife’s PortaPro and look cool in the park. Or, how about using an FM SoundFeeder to listen to whatever I want to from my mobile in my car?
The mic still works fine, and when using the phone as a …phone, all the people I talk to sound great as well!