[eluser]ascotan[/eluser]
You dont really need an IDE for PHP programming since you're not really compiling and debugging your code. A fully featured text editor with color coding is what you need.
If your on a Mac you want Coda or TextMate (my preference).
Windows can use SciTE/Scintilla or w/e.
For the love of g*d, just stay away from dreamweaver. Kittens are killed every time a page is made in dreamweaver.