As mentioned by Elizabeth Naramore on the php|architect site, there's a new version of the free debugger from the PhpEd folks that's been released and ready for download - version 2.15.5.

Updates in this latest version include:

• All php versions from 4.3 up to 5.2 are supported
• Fixed problem with profiler denominator
• Pre-compiled binaries for Win32 and Linux
• Source code

It's not going to be quite as powerful as the one that comes with the full version of PhpEd, but it is still a very useful little app. download it for yourself and give it a try.