For now, at least, PDF is still the king of digital document formats. Even with its limitations (such as fixed screen width), it can be read in the widest range of platforms–it will work in your your browser, your media tablet, and your ereader. Adding interactive or multimedia content to a PDF, however, is still somewhat clunky, with no real guarantee that the PDF will function correctly on your iPad, your mobile, or your browser.
So, if you wanted to share interactive PDFs with your students, for example, the best workaround seems to be as follows:
Create your document in a word processor with a save-to-PDF option. I use Microsoft Word for this, but Open Office and Pages have similar options. The key is to leave space for your multimedia content, whether this is video or audio. Save the file as a PDF.
Locate your media and use the tool to draw the size you would like (for video, this matters, so pay attention to your original resolution and replicate it in your PDF). When you finish inserting all of your content, save again as a PDF.
To share the document, I recommend Dropbox. If you’re more ambitious, of course, you can publish them through Google Play or the iBooks Store, but you will likely lose interactivity with Google, and you’ll need to author your document with iBooks Author for iBooks. To use Dropbox with a class, set up a folder and share it with your email list. Recipients will be prompted to create a Dropbox account, which will enable them to download the file and upload their own. If all goes well, you’ll have a small library of interactive PDFs, privately available to you and your students.
To read the interactive PDF on a tablet, students should install Dropbox, grab the file, and read it with a good PDF reader that can handle the interactive content. There are several options here, but I use the cheap EZPDF. Note: currently, Adobe Reader, Kindle Fire, Bluefire Reader do not handle multimedia content.