See this calendar of writing prompts for each day of the week. You can also access earlier months for even more ideas. Topics seem to be more suited to high school students.
Common Core in Action: The Power of a Checklist
A middle school teacher discusses how she uses checklists as organizational and scaffolding tools for
The One Activity I Recommend for Every Teacher (Richard Byrne)
Byrne, who writes the Free Technology for Teachers blog, discusses how blogs can be used for distribution, discussion, and demonstration. "A Complete Guide to Using Blogger in School" is embedded in his post.