Part of our project is a pure PHP implementation of Test::More called test-more.php. If you want to really keep things dirt simple (which seems to be Nola's goal), you can use it by itself with no framework.
A few years ago, Geoff Young and I gave a talk called Testing PHP with Perl. We thought we were being funny (in our defense, those who listened to the talk seemed to agree), but I think all we did is make our project seem inaccessible to PHP developers. Perl is scary. :-)
He also mentions her follow up post, demonstrating how she uses the framework in her examples. He compares this with his own test-more.php, accomplishing the same things. The "test-more.php" script is included as a part of the ApacheTest package or you can grab it directly from his site...
