Re: Missing __toString() part

I would suggest : a) Make sure $arr[(string)$obj] works (I see no reason for it not to). b) Look into how to support a unique identifier (-1 on a hash value). Two main questions are how this thing looks like, and whether it's explicit (you need to call some function/method to get it) or implicit (e.g. $arr[$obj]). A Unique indentifier could look something like "Classname#Object id" e.g. "SimpleXMLElement#1". Andi P.S.-Yep, sticking to bullets keeps emails brief :)