You can retrieve the public profile information for any YouTube user. To retrieve the profile for the user 'liz':
Example 454. Retrieving a user's profile
<?php
$yt = new Zend_Gdata_YouTube();
$userProfile = $yt->getUserProfile('liz');
echo "username: " . $userProfile->username->text . "\n";
echo "age: " . $userProfile->age->text . "\n";
echo "hometown: " . $userProfile->hometown->text . "\n";