How To: Read PDFs in Apple's iBooks with a little help from Dropbox
Once you've got the files uploaded to Dropbox, though, how do you get them into iBooks? Just find the PDF in Dropbox on your phone, hit "Open With" and choose iBooks. It's easy as pie, and your PDF files will automatically sync through Dropbox, too. You don't even have to bother plugging in your device or using iTunes. Brilliant!