Using boost.org within a Cocoa project is not really complicated. I'm using opaque pointers as described here: Can I separate C++ main function and classes from Objective-C and/or C routines at compile and link?
So I have written a few Objective-C wrappers around the boost libraries I'm using (Graph, Spirit,...) to have a consistent style in my programs (and to avoid contamining all my project so that it eventually becomes fully Objective-C++)
Before going on I would like to know if such wrappers already exist (as an opensource project) ?