Simple I2C modification to shields making them compatible will most controllers

Other Hardware Device Hacking
1

If you cut the 2 traces between the SDA/SCL pads and the A4/A5 pads so that the SDA/SCL leads from the shield are no longer connected to the A4/A5 pins!
Next solder a two lead ribbon cable to the SDA/SCL pads and on the other end solder on a 2 lead strip, leaving the 2 lead strip otherwise unmodified.

I made the cable about 3" long so it will reach either pins A4/A5 (on the top most shield) if the shield is on a Arduino R3 or to pins D20/D21 on a Arduino Mega2560 etc. There is no need to cut off the header pins on A4/A5, This allows them to operate normally through the shield and when using a Mega type board they are still available for other uses.

NOTE: ALL MODIFICATIONS ARE DONE ON EACH SHIELD, NOT THE CONTROLLER!

This would be a great factory modification! Any one listening?

2

I must be missing something, as I don't see the need for this. I2C is a bus, designed to support multiple devices at the same time.

But then, I don't use shields in the first place.