To me
I think a good php programmer has to understand C# and java. and nowadays with the concept of frameworks u can learn a framework like ruby on rails, and from there u will understand other frameworks of the nature in php, C# or java. something like Code Igniter(www.codeigniter.com) is a good framework for php developers who need speed in development time, and speed while the site is running. I built a full forum for cameroonians(www.passgce.com/discuss/index) in one week with the help of codeigniter. it reduces the work u have to do while development by introducing helpers much like php classess and u can add your own helpers. and if u understand the framework you can easily translate your app to C#(castel monorail) or hibernate(java) so you build one app and translate the models the views the controllers and the helpers to another language.
check it out (www.codeigniter.com) and tell me what you think or check this out http://en.wikipedia.org/wiki/Model-view-controllerto see how it operates with other languages
what do u think??