I've just purchased WebBuilder 2006 which is really making my life easier with coding PHP, so much easier infact I have persuaded my company to buy it too.
The one thing that niggles me (so far at least

Assuming that to save it you would have to create a 'working' file and a pure 'PHP' would cause problems for people, can you not have a +/- symbol in the left hand gutter where the braces are? Since these are already linked between { and } braces, I wouldn't have thought it would have been too hard.
Hopefully I haven't repeated another topic that has already been posted on the forum, I couldn't find anything exactly like this so I hope it is food for thought.
Cheers
Cyberghost