iBooks and "Read Aloud" feature

[Grafixx01#IM]

Ok, so I've updated my iPhone4 to OS 6 and all the software updates for programs are done. I've been trying to find this "read aloud" feature that someone on iMore posted here but it doesn't show up on mine. Any ideas? I am a slow reader so I figure if I purchase the books and can have them read to me, it'd be a lot better.

 

[Grafixx01#IM]

Nobody has any ideas? is there another app that can read PDFs / ePub / mobi formats out loud or through the headphones then?