I have been trying out various IDE's for this board, and have returned to mbed.org.
I have sorted out headers for the board, although like Nico you need to cut some.
The other problem is shields, there are none that suit this board, and the current offereings are not even close to the price I expect.
I have a plan, which in concept will work, but needs a little more thought to make it truly universal, and useful.
My parts for the project I had in mind got delayed, so i resorted to trying a few existing programs and adapting them to suit.
I wanted to utilise the acc sensor and while I was getting the feel for it, I came across this in mbed.
http://mbed.org/users/maclobdell/code/FRDM-KL25Z_secret_knock/
I added a couple of relays, one to operate when the right code is entered, and the other when you get 3 wrong codes.
When we were offered these Pat was after low voltage remotes as an application.
I'm still working on my app, but this can be applied as a low voltage hidden lock, that requires little else.
In order to complete this, I need to find a low voltage locking arrangement.
A servo might be one option, but I'm not sure if they work on 3v.
I do have a 5v stepper that is geared, so I might need to try that.
For the power, there are some new 3v cells (LiFePO4) available that are AA in size and shape and 700mAH (yes expect smoke when someone doesn't look), and one of these will be perfect.
In the meantime, a double AA pack will suffice.
The zip file is attached that you can unzip and import into mbed.
It has comments on the pins used for the relays, and I'll upload a photo tomorrow.
Mark
edit 5th June 2013
The attached is the review in 'The Shed' magazine which is a NZ based hobby type mag featuring 'How to' articles ranging from Woodworking, Metalwork, House Renovation and electronics.