Sony Ericsson has taken the bold and brilliant move of releasing its alpha build of Android 4.0 which can be installed on unlocked Xperia handsets.

The alpha ROM can be installed on unlocked Sony Ericsson Xperia Arc S, Xperia Neo V and the Xperia Ray handsets.

The ROM brings with it most of the features that Ice Cream Sandwich offers, but a few are limited and some are missing altogether. Google Mobile Services like Gmail and Maps aren't included which isn't so bad since Bluetooth, Wi-Fi and the modem are also turned off.

Sand in your sandwiches

Crucially, the SIM card won't be recognised, so you won't actually be able to use your phone as a phone after the install.

So needless to say, this isn't the ROM for your everyday Sony Ericsson phone – as Sony Ericsson puts it, "this software is not intended for ordinary everyday usage – it is for demonstration purposes only".

The other thing to note before you rush off to get the new software is that you won't be able to download and install the final Ice Cream Sandwich software upgrade if you unlock the boot loader in order to install this build.

Okay, enough of what you won't get. Here's what it does include: a new Roboto font (control yourselves), the new Holo theme, an updated UI in the settings, web browser, messaging and for multitasking, as well as music player control from the lock screen and the ability to swipe to dismiss notifications.

If you value a working handset too much to install the unfinished software, you can still enjoy the fruits of Sony Ericsson's labours with the video walk through below:

From Sony Ericsson via Phandroid