The following is a concept phone by a designer by the name of Antoine Berieux, and it consists of an outer shell and an inner cartridge, this inner bit being able to be switched, each cartridge containing a completely different OS or iteration of OS. Like physical ROM switching at the click of a hatch!

Generally when a designer creates a concept smartphone, or any sort of device like this, they create one single version to start with. This guy created three. There’s the Started Edition, Smart Edition, and Ultimate edition, each one better than the last. The highest grade phone you can get here is a total dream:

Qualcomm Snapdragon 1.5 Ghz Dual Core Processor
Dual Android 2.2 Froyo / Windows Phone 7 with HTC Sense
Flash: 64 GB
12.0 Megapixel camera on the back, 1.3 megapixel camera on the front
Video recording 1080p (back only, we must assume)
5.82 oz heavy
4.65 inch multi-touch capacitive 1392 x 785 pixels screen
HDMI port, micro-USB

Internal cartridge:
external memory: micro-SD up to 32 GB
Camera: dual LED flash
Audio jack 3.5 mm
GPS / Digital compass
1800 mAH battery

Fantastic. See additional images below:

[Via Yanko Design]