This blog is really useful for Apps - as they say, there are an overwhelming number of them and they cull through to find the best in various disciplines.
http://www.merlotx.org/ is the main site for the online textbooks of all different categories. The link above is for Literature but the merlotx.org site covers just about every subject. Merlot itself is a great resource but this subsection can be very useful.
Very useful videos, some long and some shorter, to help build lessons around or to supplement a lesson one has already created. TED Talks is useful as well, but this education version of it offers more potential for use in a class.
This was used in a class I took and I found it a fascinating tool to doing a poll or survey for a class. It allows students to use the tech that they generally already use to a great extent - such as responding by text from the phone using a code specific to that poll, responding via twitter, or on the PollEv.com site directly. I haven't integrated this yet into a class, but I can really see potential here after using it in a class
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