NOTE: Most of the links in this post are outdated. For more latest information, please see Telugu Localization Community in Google+.
Now-a-days, many stand-alone and web applications can be localized into Telugu online. Ability to do localizations online is a simple way to get many people collaborate. Less tech-savvy users can participate easily, too.
By helping Telugu localizations of various applications/websites, you are becoming part of realizing the dream to see more and more Telugu on the web (and in computers, generally). The below is a list of places on the web that allow translation of various applications into Telugu.