I\'ve been using pear packages in php for years. I\'m in the process of upgrading/moving a sites that uses the MDB2 pear package and it has not been updated for PHP 5.3.X.<
I would definitly go for an ORM, at least if you are working on a big project, for which you don't want to use mysqli_*
or PDO functions/methods directly -- Doctrine being the most developped/used, nowadays (It's the default ORM of the symfony Framework, and can be integrated in Zend Framework quite easily).
About the E_DEPRECATED
errors, though : PHP 5.3 is quite young, and lots of libraries/software/projects have not been adapted yet -- you'll probably have lots of those in the next couple of months :-(