Through Wesley Fryer's gracious response and guidance on Twitter more specifically a video mark at the mark of 5:40, I have decided to go with Posterous. Tumblr may offer the same services, however, my familiarity with Posterous from the 10-11 school year and the fact that ideas can be posted via email (the video explains the moderation process) or through the FREE app has led me to finalize my decision.
Now, I must simply debate whether to have students complete individual blogs or a community classroom blog for responses. If I do have students complete individual blogs, I will be placing the RSS feed into folders in my Google Reader. This will help organize the updated posts from students for easier evaluation.