Thread Filter by OP

my users are requesting the ability to filter a thread so that it only shows posts made by the OP. just something simple like a checkbox on/off at the top of the thread and then it would add a filter to the query by user ID.

I didn't see any sort of add-on that would do that or was similar enough that I could tweak, so I think I'll attempt to build it myself.

I'm a PHP/MySQL developer by trade and I'm fairly familiar with the Zend framework, but this will be my first foray into Xenforo.

any tips on where I would start with an add-on like this?