The first one is testing release candidates RCs of PHP releases. You can do a very basic test by running "make test" after compiling PHP, but it's even a lot more important to test your own code with the RCs. This often catches more things as the PHP Development Team doesn't quite know how everybody uses PHP. It's a little bit late in the game now for PHP 5.4, but head over to http://qa.php.net/rc.php for a quick intro and a link to where to download the RC8. PHP 5.4.0 is not released yet, so testing the RC is still very valuable. Hurry up though, as this is most likely the last RC for 5.4.0! Also, you are not allowed to complain about PHP 5.4 breaking stuff unless you've tested RCs :-)
The second thing that Rasmus brought up is a new feature on http://bugs.php.net It's modelled like the "random cute cat picture" features that sites like http://cuteoverload.com use for giving you a random cat picture. Except that we don't show cute cats, but a random PHP bug. If you have a few spare minutes go hit http://bugs.php.net/random until there is either an unconfirmed bug report that needs triage, or perhaps you can just fix it because you're a C wizzard. This is hopefully a better time waster than random cute cats.
Oh, yeah, go test the PHP 5.4.0 RC! 🐱