As Greg Beaver mentions in his latest blog entry, the main website for PEAR, pear.php.net has been mirrored as part of an effort to restructure and "revamp" the PEAR wesbite.

I'm excited to announce the first two mirrors of pear.php.net are now actively mirroring the installer REST files and actual .tgz files of package releases. They are http://us.pear.php.net (provided by Joshua Eichorn and bluga.net) and http://de.pear.php.net (provided by Christian Weiske). The option exists at a future date of mirroring the entire website, but this will not be possible without further changes to the infrastructure.

Using these servers is only slightly different than the main site, setting the preferred_mirror setting in your configuration to use one of the above.