I have a 16g Ipad3. I do not want to jailbreak it, but may have to. Am looking for an option to put expanded/external memory on it and have it read PDF files that I use for work. I am currently using dropbox to download as needed then delete as needed. Any other options? I understand I can use a usb stick if I fool it in thinking its a camera. But those are for Photos and Videos and I want to read pdf files. Thoughts?