Locating similar websites can be a challenge--here's a quick way to seek alternative websites. Looks interesting! Good to share with kids too. I think it could be described as a targeted search engine.
Description is an inexpensive (.99) iPad app that allows you to explain a website, record (screecast) computer screen and voice and annotate. It looks really helpful.
Department of Education--information on not blocking websites. A must read for educators (and to forward to those in control of 'unblocking' websites!)
Collaborize classroom looks very interesting and it's free. Encourages student engagement, shares lesson plans and more. Pretty strong endorsements of website as well. Worth checking out.