As I read through some of the responses to this question, I noticed that there was a great site listed for 2nd grade. This made me curious as to whether there was an extension for 5th grade...and there certainly was! The site is https://ep-storytown.wikispaces.com/5th_Grade. It intrigued me because of how closely it aligned with much of what I teach: grammar, parts of speech, punctuation, etc. When I clicked on one of the activities for punctuating sentences, I was pleased to find a colorful activity that was clear in direction and purpose. I could envision using this site as a tool for practicing and reinforcing concepts in the classroom. It seems both informative and fun in nature!

www.twiki.com was an interesting site.  It was not an education site but rather a business site.  This is an example of how business communications are evolving and evidence that we need to teach our children now, even if these things are outside of our comfort level, because they WILL be using them in their adult lives.

www.wikidot.com was another site I found to be interesting.  They boast the following points:

• "discuss research topics and collaborate with coworkers,
• publish lesson / lecture notes and materials, including any PDF files or PowerPoint slides,
• inform students about upcoming topics and events, also using RSS feeds to keep them up-to-date,
• publish homework tasks,
• create forums to discuss topics,
• organize whole classes using Wikidot,
• create separate wikis for groups or for each student"

The site also offered interactive modules to have on your wiki, from video and pictures to RSS feeds and del.icio.us bookmarks.  The site is geared towards education and has a free and a professional upgrade option.  I like the amount of space that it allows and also the interactive modules in one place.  Its nice to not have to recreate something every time!   

http://mmethomas.wikispaces.com/

This space is cool because it shows how to create games that you can use with Quia.com (which I'd never heard of).  These games can be put on your website for the students to practice at home. 

Doing a google search, I found an interesting wiki for second grade. What I liked about it is that there are both kid friendly and teacher friendly areas of the site. Some items are pdfs for the teacher, and others are interactive for the kids. I was immediately drawn to the "Character" page. Students can click to "create" a character changing the appearance and then use the notebook to write about their character. Very fun!

The Cool Cat Teacher Blog appears to be outstanding.  It focuses on differentiated instruction, with most recent posts related to the incorporation of technology.  Podcasts are included in the wiki.  All of my students require significant differentiation in the curriculum.  As a member of collaborative teams focused on differentiation, the sharing of ideas with this site may prove to be a very helpful resource.