On the PEAR blog today it's been pointed out that many PEAR packages are moving to github as their standard place for development and repositories under the pear and pear2 accounts are available for anyone wanting to make the move.
While the existing PEAR packages will continue to use the pear.php.net distribution and bug tracking capabilities; it's never been easier to contribute to a PEAR package - simply fork; add your changes and send us a pull request. If your preferred packages aren't yet on github, please feel free to drop us a line on the pear-dev mailing list.
Here's more about the process to get the repository set up and how to migrate your package's current code from SVN over to github. The transition's pretty painless and can make the social development and improvement of your package a lot simpler.