Like many librarians in the state, I've been aware of the ELM resources for some time - we make extensive use of the ELM databases in teaching. One thing I've learned, though, when talking to friends who aren't librarians, is how few of them are aware of these statewide resources. (Every single one has been amazed and delighted when I explain, mind you - but they didn't know they were there.)
Looking at the tasks in this Thing made me feel somewhat the same way: we use the databases for article searches extensively, but I hadn't explored the multimedia options much at all.
I'm also reminded of the benefits of NetLibrary: one of my interests has to do with a topic where people sometimes complain that it's hard to get access to books: a number of books on the topic (a religious one) are available in NetLibrary.
That said, as comfortable as I am reading online text, I find the NetLibrary format still rather clunky: I read fast, and the 'page turn' speed of reloading is slow enough that I tend to feel frustrated if I read at any length. I have an easier time with full screen PDFs, as I see more of a page at a time (and therefore have fewer pauses to reload the screen).
I intend to continue playing around with more of these tools, and bringing them up with specific teachers who might find them useful.