Quick post today. The two websites above are aggregators, of sorts.
Scoop.it allows people to curate links to resources they've found online. I've found topics related to Latin, and know there must be others important to educators.
Mobento collects videos from many sources (Youtube, TED talks, etc). What is nice about this is it also scans the audio of the videos for keywords. So when you search, you are getting a more accurate result for the topics you want.
There are more than these two sites, but off the top of my head these are really good.