We all need resources that are quick and easy to use. As a teacher finding connections is the hardest. Here are some of my favorite Wikis:
Skye in Schools Allows you to connect with other classrooms easily.
PBWikis Contains directory of wikis for education and much, much more!
Teaching with your IPad This wiki has tons of information about IPads and even more ideas on how to use them.
Cool Tools for Schools This wiki has Web 2.0 tools for everyone and every thing you can imagine.
Wiki for Twitter in Schools Classroom activities and ideas for using twitter in a classroom.
These are just a few a use on a weekly basis--I'll keep adding as time allows. Enjoy!