Since upgrade to iOS my phone does not remember position in audiobooks
I found this solution to work:


Plug in your iPhone (or iPod or else, here we'll assume an iPhone) , fire iTunes
In iTunes, select all the songs in your Music (not in your iPhone)
Right-click and choose "Get Info"
On the window appearing, choose the "Option" Tab and select "Yes" for "Remember Playback Position"
Click OK to save and then synchronize your iPhone (depending on your iPhone synchronization settings, it should take over the changes from your Music to your device)