There's plenty of treasure in API docs, I've usually found--like when you need two submit buttons for an AJAX form. While tutorials are helpful for just getting started, I'm a firm believer in just browsing through API docs and references once in a while, like a lazy grounds keeper checking for garden gnomes. I also like reading dictionaries. I don't do that too often, just when I'm looking up words. I never got any papers done until internet dictionaries came around.
As a result of browsing through the Prototype API, I found that the adaptive polling I had talked about before was actually already in the Prototype library. It was just never mentioned in any of the Rails docs or tutorials about periodically_call_remote().
Though I don't know if it was around when I blogged it last December, that should be lesson to me to stop talking, and just try writing a patch, as Prototype is open source. I probably would have learned a lot.