I have used Let's Plays when tutoring to help encourage my students to use their literacy skills in an area that they were already familiar with. The two boys I did this with were both ELL students who happened to have an interest in video gaming. Web 2.0 projects have the benefit of asking students to reach a wide audience on a subject they are interested in while simultaneously giving them the ability to perfect their work before presentation. One of the things I liked about using a LP with these two boys was they were able to practice using both BICS and CALP. BICS is utilized when they are responding to posts and recording the narration to the video. CALP is used when defining vocabulary words and writing discussion questions. In my example, I used video game terms as my vocabulary but students can define any difficult word used either in their game (dialog, menus, written files), narration script, or discussion questions. For my demonstration LP, I recorded my audio live and did not write a script for my narration. I would make the decision to record live or in post-production based on the BICS needs and personality of the individual student. I think both ways have their merits and flaws.
To tailor a LP for educational purposes I added a few elements that are traditionally not part of a LP. First I added a vocabulary section where the player lists words that the viewer will need to know. In addition, I also added discussion questions. Sometimes in the course of a LP the player will ask for viewers to vote, I simply formalized it with a discussion question section.
When recording my video I chose to use Procaster, which is available as a free download. Procaster requires you also link your video to a livesteaming site as well, which is the one downfall to this product. While streaming your gameplay live Procaster can save a copy of your video on your hard drive. Fraps is also an option for recording video, which does not require a connection to a livestreaming site. Fraps however, is not free and the video file type it saves as (.avi) sometimes has compatibility issues with later versions of Windows Movie Maker.
You can watch my LP of Costume Quest here.