Using the iPad in the classroom - this article discusses History specifically, but could definitely be modified for any subject. Also, provides links for digital textbooks, which are most likely the wave of the future classroom.
A very useful tool for middle school and high school teachers, and maybe even later elementary grades. Not very useful to me as a first grade teacher, but when students are asked to do research papers, and they start citing Wikipedia as a reliable source, teachers should utilize this. :)
For any middle/high school teachers who plan on having their students write research papers - to avoid Wikipedia and other unreliable sources students may find via simple Google searches. :)
I found the lesson plans tab and the professional development sections to be the most useful for teachers like myself. I would need to do a bit more investigating to decide if the student centered search engine is useful for elementary students.
I know other people have posted Ben's Guide, but here's the K-2 section of the web site, which includes games and activities, as well as additional links and resources for the students. I particularly like the subtopic about "My Neighborhood," as it is relevant to what I will be teaching my students in my own classroom and I love supplemental material!
Ben's Guide to US Government, K-2. Includes sub topics relevant to the grade I teach, including "Your Neighborhood." Website also includes games and activities, lots of visuals and videos, and also additional resources and websites for the students to explore.
I know field trips are not as easy to organize these days, but here's a link of Florida field trip locations I found on the DoE web site. A lot of these locations have pretty cool interactive web sites that offer "digital field trips" which could be an alternative.