Hi. This is my first instructable here, and I'll show you how I did my Book Flash Drive. Also, please be easy about my vocabulary, I'm not American... but I think you should be good with the pictures.
Oh, by the way, I've checked if this idea is already posted here and I found nothing.

This is those who want to: - Show something curious to friends.
- Avoid getting their flash drives stolen (if the book looks boring)
- Have a bit of fun while bored, if the book is goods (like a jokes one)
- Make your book a bit more useful.
- Make this just because yes.

In short terms, this one is pretty easy to do. You may only need:
- A tiny book.
- Flash Drive (medium sized, not squared like those Kingston Mini Fun, and not larger than the book of course)
- Something to cut, like a craft knife.
- A small stick
- Hot Glue/Super Glue.

Step 1: Opening Your Flash Drive.

Take your USB stick and look how can it be opened. Maybe you'll require to use brute force, by opening it with your craft knife or whatever. Just make sure you don't go too far, as you may break your USB stick.
At the end, it should look like in the picture.

Step 2: Preparing the Book.

Basically, the flash drive will be put inside the hole in the middle of the book, as shown in the first picture, but we're going to make the usb stick retractable.

Put your drive next to the middle of the book and measure it when it's outside and hidden, as shown in the second and third picture. You need to mark in the book a line according to: the middle of the rectangular thing of the drive when it's outside and hidden.

Step 3: Making the Holes.

Now we are ready to cut. Make a hole according to the line we marked.
NOTE: If your drive has a LED outside the hole made, make a little hole where it should be when the drive it's "outside". In my case, the led was visible in the hole, so no problems.

Oh, and be careful making them. Try not to break your book, really.

Step 4: Making It Retractable.

Now, put your drive inside the book, with the usb conncector hidden. Take your plastick stick or whatever and glue (hot glue or super glue) it to the middle of the rectangular thing (or wherever you want to stick it, just make sure it can be hidden and outside). Wait for it to dry.
Looking to the picture may help better.

Step 5: FINAL TIPS

So there you have, a retractable, mini book skined, flash drive. Easy, don't you think?

- WHEN YOU ARE UNPLUGGING IT FROM YOUR COMPUTER, PULL YOUR BOOK BY THE STICK; OR ELSE THE BOOK MAY RIP, UNLESS ITS CASE IS REALLY HARD.
- FEEL FREE TO COMMENT AND RATE :)