I think it is vitally important for teachers to plan for technology when planning for the content because ideally the technology should serve as a vehicle for learning, not as an "event." In order to ensure against "Remember the time we used _______?" content must be the focus with technology being seamlessly woven into the learning goals.
Accountability goes a long way in not only character-building for our
students but also in the preservation of the tech devices. Students have to be aware of the fact that these devices are not meant for "fun" only but rather as another tool in their learning process. Often when I create centers I have a split between 3 different tech tools and 3 "traditional" tools where each have a set of open ended questions that students must answer. This way students learn in different ways and gives them options as far as expanding their skill base.
Of the sites listed, I will like to use Museum Box since it seems to be an interactive way for students to take a small piece of history and expand their knowledge. Another great site is History Buff which will allow students to research primary sources and for them to "see" it as it happened. As far as Apps- I really like the Smithsonian Channel for iPad where I can create my own "channel" for student use. (There is also one for PBS). There are also lots of review apps for the AP exams and practice tests that I am excited to use in the spring. I am also excited about being able to use iTunes U to help with differentiation. Students could have these split up to create stations.