The transliteration tool is especially nice. For example, it automatically converts "ramesh" to "रमेश". If you did not want the word automatically put in by the tool, you can select the desired word from a set of alternatives or explicitly type it out yourself.
Note that you might have to tweak things a little to correctly display Indic scripts.
Update (2007-08-23): QuillPad seems to have been in existence for some time now and has support for more Indian languages than the Google transliteration tool (which only supports Hindi at the moment).
Update (2007-08-29): Raftaar also allows you to search in Hindi using a transliterating interface.