Indic transliteration is another product (after search and gmail) from Google which has all the characteristics (you can argue about my choice of criteria but then this is my blog 
) of brilliant software - No frills, doesn’t attempt to do a lot of things but does what it is supposed to do really well.
One, it’s fast. It doesn’t make you realize that it’s running in the cloud and not on your box. More importantly however, I was amazed by the accuracy of transliteration. Don’t believe me when I say it’s really really good, try it! (At least the Hindi transliteration works super, I can’t comment on other languages)
I tried being smart by throwing different ‘potential’ english representations of the words but it recognized almost all of them without any pains. Comparing it to some other transliteration softwares I have used in the past, I would rate this way above any of them.
Kudos and thanks to Google for this 
Try this http://baraha.com/BarahaIME.htm for a more general solution… seems to work flawlessly for me!
Tried it but I didn’t find it as good as google
It has the same set of problems as a number of others that I have tried in the past - It tries to do the conversion character by character. Looks like all these programs are based on some sort of a character map - a sequence of characters on language ‘X’ maps to a unique sequence in language ‘Y’ so that there’s only one correct way of typing a word. You need to type in the exact sequence of characters to get it right.
Not so with google - it converts word by word and is much more intelligent. It handles ambigous cases pretty well and also adapts to your style. And it is damn fast!
I’d so love an offline version which integrates with office and other programs like the one you have pointed out but there are none that I know of which do as good a job as google in terms of accuracy and typing usability.
यह तो है पर फ़िर ऐसा कोई software भी तो नही है जो browser के अलावा और जगह भी चले… इसमें शब्दकोष भी होता तो और बढ़िया होता