Now, you can type directly in Devangari script on any text field on any website. Thanks to http://code.google.com/p/t13n/
Just drag the link below to your bookmarks bar:
Drag this link to your bookmarks bar
How to use
After a webpage loads, just click on the bookmarklet to enable it. After enabling it, you can type in Devanagari on any text field on that webpage. Just type the words in English and it will be transliterated to Devanagari.
There are many other supported scripts. Please visit the project’s homepage for other bookmarklets and more detailed information on using it.