Chris Jones has posted a quick note to his blog today about some new PHP packages that are available from Oracle of 5.3.8 (RPM) with one of the latest OCI8 extensions already included.
I've built PHP 5.3.8 RPM packages with various common extensions (and the latest OCI8 1.4.6) for Linux x64. They are downloadable at oss.oracle.com/projects/php/. These binaries might be useful for quick testing. They are unsupported.