I can't believe how little stuff there is for YUI so I'm having to do it the hard way by writing classes to give me the YUI outputs and dependencies myself. As my needs at this time are a small subset of the full YUI functionality these classes will not be 'finished' and all I'll do is tweak as I want to do something else.
For example I've got a 'yGrid' class that does all of the writing a table stuff in 15 simple lines and by the end of today will have sorted out dialogs enough for my purposes.
If anyone else is thinking "this YUI stuff looks good, but I could do with it wrapped up in some easy to use PHP" and would like to cooperate then please get in touch so we may end up with at the very least something to whet other's appetites and give them a kick-start in using YUI.