Meanwhile, the first step required me to trim down my SD card. Here is a photo-tutorial of my steps!
1. Buy a cheap SD card.
I used a SanDisk 2GB card, for 7 CHF = $7.55 in InterDiscount. This will void your warranty - you have been warned!
Maybe we should maintain a list of cards that have been successfully cut?

2. Test the Raspberry Pi before cutting the SD card.

3. Draw a line on both sides of the SD card using a permanent marker.
I first used a pencil, but my fingers made the mark rub off. Use a marker.

4. Use a powerful light to check that there is nothing in the lower half of your SD card.
I used my iPhone 4S flashlight, although this picture is using my Pico Projector. Make sure that you can't see anything below your mark!

5. Pry open the SD card with a screwdriver, and make sure there's really nothing inside.

6. Attack it with scissors! Follow the line as much as possible.

7. There really was nothing inside. Phew! That's a relief.

8. Use a file to make the edge smooth.

9. Seal the end with superglue.

10. Cover the superglue in filing dust to add some surface area. This helps in sealing & colouring it.

11. Colour the filing dust with a blue marker.

12. The SD card now sits flush with the motherboard!

13. Put it back into the case.

14. It boots! Time to celebrate.

I think that we should maintain a list or photo gallery of compatible SD cards, that have enough free space to be trimmed in this way. It was cheaper for me to do this than order a low-profile adaptor from Adafruit.
https://www.adafruit.com/products/966
Peter