Nastaliq script is beautiful but it's difficult for computers to render. Typing in Nastaliq can also be rather difficult. I think this is why so many people use Roman characters to write in Urdu, e.g, writing "meraa naam Sam hai" instead of "میرا نام سیم ہے". Fortunately, there are new tools to help with the input -- so, assuming you've learned to read Nastaliq, there's no longer any excuse to write Urdu in Roman characters! (If you haven't learned Nastaliq, I would suggest the Richard Delacy book "Teach Yourself Urdu Script," which I found very helpful).
First, Google Input Tools makes it easy to convert phonetic Roman characters to Nastaliq output. So, for example, typing "Urdu" results in the output اردو. You can download the appropriate tools here: http://www.google.com/inputtools/windows/. Instructions in Urdu are here: http://www.google.com/intl/ur/inputtools/
Second, Google has just released a beautiful new Nastaliq font. It is much nearer to proper, handwritten Nastaliq than other fonts. You can read about it here: http://behdad.org/urdu/
.... and download it here: http://googledevelopers.blogspot.com/2014/11/i-can-get-another-if-i-break-it.html
I have not yet experimented with the new font but it looks promising.
I hope that over time these tools will allow all of us to easily type in beautiful Nastaliq!

