Google's transliteration feature has been of great help to Indian's looking to type in their own languages. But to use it one had to be connected internet.
But our dear Google (G capital for God and Google) has again come for our help. They're providing an IME tool which when installed works as a new language in your windows system (yeah that language bar you tried so many times to hide, you're gonna need that)
You can just type in the language you choose even in notepad.
Google Transliteration IME is currently available for 14 different languages - Arabic, Bengali, Farsi (Persian), Greek, Gujarati, Hindi, Kannada, Malayalam, Marathi, Nepali, Punjabi, Tamil, Telugu and Urdu.
First you'll have to download the language pack you need from this page.
And don't cut the internet connection
Then when you run the file it will download the files it need, install itself and disappear into nothingness.
Then when you're clueless about what to do, go to the Google Transliteration IME help page Google Transliteration Input Method (IME) Help there. (You can't find that link by searching, they show some Chinese pages, so rather save it now)
There, they will tell you to enable the language bar (by right clicking on taskbar, pointing to toolbars, selecting language bar) and then to select your language to see the Google IME.
Rest is explained nicely with pictures over here:
Google Transliteration Input Method (IME) Help
Just go there, start typing without pain...