Google, Live Search and Yahoo! have all been supporting Unicode text searches for years. Using them you can type a tamil word in Unicode and search. Google also gives you a Tamil User Interface if it detects your Browser Language setting to be”TA” or “TA-IN”.
The constraint in using them were, you needed to have a Tamil IME pre-installed in your machine. Microsoft provides its IME for Tamil free with Windows XP, Vista and more through their BhashaIndia Website, my favourite has always been my good friend Malaysia Muthu Nedumaran’s Murasu Anjal due to my bi-lingual typing, Apple bundles Anjal now with its Tiger OS and above, Fedora Core 6 bundles a free Tamil IME. But inspite of all this, if you need a no-install way to use Tamil search here is a new site that is build on top of Google API that allows Tamil Unicode input through English typing. Check it out.