Apple has freely released its Sangam MN fonts present on the iPhone 4 and iPad.
I have created a font for Mac users who wish to read and write in Telugu (తెలుగు). The font is a Mac version of Pothana, a typeface by Dr Krishna Desikachary of Winnipeg, Canada. It's not yet finished, but is being released in the present workable state and users are requested to give feedback, especially if you find font bugs. The version presently available has been revised by Abbul Chowdary Thammineedi to fix a vattu placement that he had found.
To install, put the font in ~/Library/Fonts/
Once you have installed the font, you may then change your browser setting to request Telugu pages first. Your browser is currently set to request United States English pages. Do this by going to the System Preferences, click on the International icon (United Nations flag), Clicking the Edit List… button and enabling Telugu, which will be near the bottom of the list that appears.
The font works with any version of Mac OS X and is released under the GNU General Public License. You can download the morph input file for Pothana if you so wish.
Thanks to Hari Prasad Nadig for invaluable help and guidance with the Kannada language and script, given whilst I created a Kannada font, and which was useful in this project too.