I want one feature added in iOS 7. What one feature would you add?

You know when you are composing an email in iOS Mail you can long press and get the option to "insert photo or video"? I want, directly beside that, the option to "insert PDF". When touched, a selection window will appear showing the collections in iBooks. Yes, only iBooks. You can select an iBooks collection (I have one labelled PDF but that would not be strictly necessary), then choose a PDF file only. Other files like books will simply be greyed out.

It would be directly analogous to what happens when you touch "insert photo or video" and a selection window opens up where you can pick from your albums, then pick a photo or video.

Why? I am iOS only (post-PC for a year now) for all sorts of reasons. The one real annoyance is when I am corresponding by email and need to attach a PDF while in a threaded conversation. It is a total PITA to have to break out of the thread and do the ritual of starting a separate email from iBooks where I keep my PDFs (usually but not always scanned documents) and have this out of thread email. Of course I need to explain what is going on in the thread first, then title and annotate the orphan email to make it as painless as possible for the recipient, but it is still a clusterf***.
That's it.

If you could choose the one specific feature added to iOS 7, what would it be? Yes this hypothetical iOS 7 will change by only one feature and you get to pick it.