I'd like to suggest that a wiki might be a useful tool for some of the tasks you've recommended. I'd be interested to know when you would use a wiki and when a blog would be better suited to the task.
Wikis are very powerful tools. And yes, I do use them regularly with classes. Now, one way to go about it is to create a new wiki on Wikia. I'll post on how to use Wikia a bit down the road, as it has a number of complex figurations that I don't want to get into just yet. But advanced readers should explore widely. We use Wikia here at school as a way of communicating with alumni and creating a comprehensive collaborative school history.
To make Wikis in class, I use a much simpler option: Google Docs. These are collaborative documents -- typically Word and Excel documents -- stored online and accessible by a 'team' you create through Google. To get started: go to Google, click on Docs, create a new document, and add/invite collaborators. All you need to start working is a Google ID.
Once you have added collaborators, in effect you have created the environment to make a quasi-wiki. The basic difference between a G-Doc and a Wiki is that you can limit the members of the party editing the G-Doc, which makes it ideal for a classroom situation.
Start with a simple project: Create an encyclopedia entry. Say you have twenty students in your English class. Split the group up into pairs, ideally each student on a computer. Choose a topic like, say, English Romanticism. Assign each pair a sub-section like Wordsworth, Byron, Historical Context, etc... Each pair will then research their sub-section online gathering information, images and video, and hyperlinks to sources. The pairs will then enter their findings into the G-Doc. The beauty in this is that all twenty students can be working gathering information and images and entering them into their sections on the SAME doc at the SAME time. That's what makes it collaborative.
Now take it to the next level. Once the basic sub-sections are finished, have each student pair edit the work of another student pair. They should add more images, check the links, and create MLA-format bibliographical entries for each. These will be placed at the bottom of the doc.
Now you have a complete encyclopedia entry with a comprehensive hyperlinked bibliography. Perfect for test/exam review as well as a jumping off point for research work.
On top of all of this is the fact that you are also a member of the G-Doc party. So on your own computer screen, you can see the work of each of the students as they enter information, images, and links into the doc in real-time. Meaning that you no longer have to wait to get a 'final-product' to gauge how students are comprehending the material. Rather than receiving something 'finished' which contains errors that will ultimately prove to confuse the student, you will see errors being put into the doc in real-time which then gives you the opportunity to correct the students or raise questions to the class for purpose of discussion.
And if you really want to up the ante, just consider the fact that none of this actually need be done in the classroom. You could just as well schedule a 7PM wiki-session on a Tuesday night and in 45 minutes of homework time have the students complete a document ready to use the next day in class.