I've just downloaded OB Session (which is brilliant) and during my initial tinkering, I wanted the profiler to display the session data so I could keep track of what I was doing.
Now, just to warn you, it's a bit messy and I provide this with a "use at your own risk" warning! :)
Currently, it will display the userdata, and session data separately, with their own headings under the fieldset 'SESSION DATA'. It also colours new and old flash data red and green respectively, so you can keep an eye on that. It also supports the native CodeIgniter session library, too, and will switch to a more basic view if it can't find OB Session (currently tested for by checking for the 'ro_userdata' method, which I realise is a bit of a bodged way of doing it, but hey, it works for my needs!)
Again, this was just for my purposes, just found it useful so I thought I'd upload it. Just drop the 'Profiler.php' file into your application/libraries folder and add the language-file lines to language/english/profiler_lang.php
I hope it works ok :-S