How can web2.0 technologies facilitate classroom-based group work?

In a recent posting, I discussed how I thought the shift in use of technology in the science classroom would place the emphasis on collaboration, rather than on instrumentation (but without losing the many great data collection and analysis uses of technology we now employ). I've been thinking more about how collaborative and communicative uses of technology can enhance group work in the science classroom.

There are many types of collaborative grouping employed in science classrooms: group problem solving, group lab activities, pair-share, peer tutoring, jigsaw, and student teams/games to name a few. I'm sure there are many others. What are some ways in which web2.0 communications technologies can contribute to science classroom-based group learning? I'm thinking of technologies and specific applications such as chat, video chat, blogging, microblogging (e.g. twitter , cirip.ro, edmodo), online collaborative document/spreadsheet/presentation construction (e.g. Google Docs), and many others.

What follows is a brainstormed list- I certainly hope others will add to it though comments, etc.

• Extension of group working time: I think the most obvious enhancement has to do with "extending" the time that groups are able to physically spend working together. Continued collaboration via email or chat is not uncommon, but what other possibilities are opened up by things such as Google video chat, nearly synchronous document authoring in Google Docs, desktop sharing applications (e.g. Microsoft Shared View), etc? I'm thinking of this category of use in a synchronous way, with all (or many) group members collaborating and communicating at the same time.
• Online workspace: Related to the above but conceptualized in more of an asynchronous way is the idea of an online workspace for student groups. Within a classroom Ning or webpage, students could have their own group space in order to share ideas, documents, solutions, etc. Think of this as an online lab table or whiteboard.
  
• Working group updates, or "a-ha!" sharing: One really great potential application involves the anytime updating of the group with new ideas or breakthroughs. Because mobile devices make sharing so easy via text message or microblog post, members can notify others when they have an "a-ha!" moment or just an idea which pertains to the group work. More importantly, a record of that idea then exists in the cloud, ready to be harvested and fully documented/explicated later on (see Documentation below)..
• Sharing of group work to an outside audience: Many teachers are already using blogs as a medium for their students to share their work with a larger audience. This is a very powerful idea, and increases greatly the authenticity of the group product. But that sharing shouldn't end with the posting. The blog post/web page/document/presentation (i.e. whatever artifact gets published) should be advertised to a target audience and serve as a context for developing communication and collaboration with that audience. For example, a student group could post their solution to a complex problem and solicit a network of individuals (perhaps starting with the teacher's personal learning network, or PLN) to give feedback on their work. This would hopefully lead to network building by the students themselves. 
• Documentation: Perhaps one of the most tangible and useful aspects of using web2.0 technologies for communication and collaboration is the ability with which interactions can be documented. Online chats, tweets, posts, web pages, collaborative documents, etc all exist somewhere in the cloud. This data can later be mined and compiled if the need arises. Of course this also presents a bit of a challenge as different formats and searching methods make this a complex task. However, herein lies an opportunity to develop more 21st century skills.

I'm sure there are many more ideas and applications for using these technologies to enhance science classroom group work. Please let me know your ideas so we can develop this thread together. Post a comment or tweet me (@Bud_T) and I'l add it here, citing you of course.