Linoit - (http://en.linoit.com/) I LOVE this site! This creates a virtual bulletin board with various backgrounds. Place sticky notes with due dates, images, videos, etc. This could be a great launching pad for your classroom if you display this on your screen at the beginning of the period or a place to organize resources for a project. Items can also be added from a iPhone/iPad (no android apps at this point). Items can also be added by email.
PBS Learning Media (http://www.pbslearningmedia.org/) is a collection of all things educational on the PBS website. The categories include Arts, ELA, Health/PE, Math, Science, Social Studies, and Professional Development. Resources can also be searched for by grade level, media type and resource type, A login is required, but access is free. resources include interactives as well as videos, documents, audio and pictures. A wealth of resources worth checking into.
Science Links:
Periodic Table of Elements (http://www.periodicvideos.com/index.htm) - videos for each element, some more entertaining than others but does a good job of explaining the properties of each element and getting a good glimpse of what they look like.
Web Adventures ( http://webadventures.rice.edu/) - created by Rice University this teachers science through role play and web games. Topics include infectious diseases, impact of alcohol on the body, the neuroscience approach to substance abuse, become a member of CSI and learn to solve crimes with forensic techniques, and explore science as an apprentice. Well-done and thought out this site deserves a look!