NOTE: We have launched our own project page for writing in urdu (from roman to urdu! the best simple and easiest way). Check it out here: Write in Urdu.
Early in the morning on a Sunday! i was online on facebook and was doing some browsing too, i got a message from one of my college fellow asking: HOW CAN I WRITE IN URDU ON FACBOOK WALL?
So here we go with way to write in any non-english language on any website, but with specific focus on: How to write in Urdu on Facebook Wall.
Write Urdu on Facebook wall by copy/paste text copied from 3rd party source
Well, at first it might sound weird, but yes, there are couple of websites available online which allow you to type in urdu online and then you can easily copy that text written in urdu and paste it on your facebook wall/share place and post it there.
You can use the following sites to type text in urdu online and to write your name in urdu for facebook or other websites (Please add any new/better sources in the comments to improve this list)
WriteInUrdu.com
Write In Urdu – a project by Nabtron provides you the option to write in urdu the easiest way by typing in using normal english fonts and they convert to urdu themselves! try it out!
Other options to write in urdu online
Google Transliteration for roman to urdu – (My favorite, thanks to Ammar!)
http://www.forumpakistan.com/urdueditor.html
http://tabish.freeshell.org/u-trans/u-otf.html
You can simply goto the above linked websites, write your sentences in urdu online and then copy the text generated and paste it in the facebook wall/share and post it there! :)