Although it is easier I think for someone to transition who already know C/C++ to move to PHP, there are still a lot of pitfalls one might encounter on there road to PHP Uberness.

I found this little tutorial called From C/C++ to PHP by Alexey Smirnov. Alexey discusses some interesting topics such as Avoiding references misuse, Object construction and Regular Expressions.

Another good read is by a user called cable_guy_67 which shows you code by code comparisons of what it would look like in C++ and then PHP. Check out Porting Code from C++ to PHP.

On the opposite side, I also found an interesting tool that translates PHP to C++, you can find the source of the tool on The PHP to C++ Translation tool page, and check out the PHP2CPP Feature Summary page to see what the tool can do for you.