Here are some useful Wikis that I have found:

http://roosevelt5th.wikispaces.com/ Wiki that is easy to navigate and gives Alphebetical lists of words for topics.
http://monarchcenters.wikispaces.com/ Not open for membership but has available a variety of games

http://smartboardresources.pbworks.com/w/page/15606709/Elementary-Science-by-Topic

Site for science topics for variety of grade levels, searchable by topic or grade level. Links to a multitude of lesson plans

http://djainslietech.wikispaces.com/
Ideas for use of Smartboards in the classroom



Please feel free to add favorites of your own!