For Arabic speakers who are sitting at a PC with a Roman-based keyboard (such as English), your life will now be easier. Microsoft Maren is a Windows extension that comes to the rescue, allowing you to type Arabic in Roman characters (Romanized Arabic, Arabizi, Arabish or Franco-Arabic) and have it converted on the fly to Arabic script.
This works in Windows Live Messenger and most other Windows applications. Notice how the Messenger client pictured here is in English, but the person typing is given the option to select the word in Arabic.
Congratulations to Microsoft’s Innovation Lab in Cairo for building this!