As you may know Notepad++ is my preferred development tool for PHP, and two months back I found FunctionList plugin that shows list of function in a opened PHP file, and it increased my productivity almost immediately.
Only drawback was that it showed just function list and not variables.
And today I found this neat patch of this plugin by Geoffray Warnants which now makes it even better with icons and also showing variable.
This is how it looked before
This is how it looks after the patch
Download the patch here (post is in French, scroll down to download the patch)