This FireFox bookmarklet allows you to write in Urdu on the web without
the need for systems' Urdu keyboard. Open a webpage with a input-box
where you can write. Write pretending that you are writing with Urdu
phonetic keyboard. Click on the URDU button on the FireFox toolbar and
the text in the box will magically convert to Urdu. This "bookmarklet
keyboard" works in the FireFox web browser on all operating systems.

Get the bookmarklets from http://geocities.com/urdutext/

The FireFox Urdu keyboard, for example, works on the following sites:
GOOGLE
GOOGLE-GROUPS
JANG
GMAIL (BASIC HTML MODE)

On GOOGLE's search box, for example, type:
aslam elikm

Now click on the URDU button (the bookmarklet) on the FireFox bookmarks
toolbar. The text will convert to Urdu:
اسلام علیکم

When writing assume the CRULP's phonetic keyboard layout.

For sites, where the bookmarklet won't work, there is a second PAD
bookmarklet, which open a TEXTPAD window, in which you can write, and
then convert to Urdu with the first bookmarklet. The Urdu text can then
be CUT-n-PASTE anywhere.

The bookmarklets are written in javascript, so the script can be
inspected (and modified). By changing the mapping table, it can support
other non-Latin languages, certainly Arabic and Farsi.