Does anyone know if there is any way to password protect either a single document or (better) a collection? I would like to store some documents I'm creating in my research on my new Kindle but only if they can't be seen by anyone who shouldn't see them.

You can password protect your kindle (after you have the latest kindle update)

With the Kindle on the Home screen, press the Menu button
Scroll down (with the 5-way switch) to Settings and press in to select
In the Settings screen, you should see Device Password at the bottom of the list. Scroll down until the words turn on is underlined (selected) and press in on the 5-way switch to select
A Set Password dialog will appear. Enter the password you want to use, Type it again to confirm it.
Enter a password hint to help you remember it
Select Submit when finished



Or you can password protect individual pdf's .....

Thanks for replying, I'd spotted the Device Password option but that's not really what I want.

You mention protecting individual PDFs, is that something that can be done on the Kindle or does the password have to be set up when creating the PDF in the first place?

You usually do it when you create the pdf. I think there are various bits of software like nitro pdf or whatever, that will edit, create and password protect pdf's. I would do a google for "password protect free software" ....

There are tools that will remove passwords as well by the way .....

You can password protect the PDF themselves which would be the most sensible thing to do but I don't know if the kindle can read password protected PDF ?

Also how are you planning on transferring them to your kindle ?