Many of you may be asking, "What is 20% Time?" 20% time was developed in the corporate specifically by Google. They allowed there employees to spend 20% of their time on projects that they were passionate about. This gave birth to some amazing products, for example gmail started out as a 20% project. The real key to this is not necessarily the projects that become a product, but to keep your employees passionate about their job.
In the schools we face the same problem. We have a classroom full of students who lack real passion for learning. 20% time allows students to work on a project that relates to a project they are passionate about. While the projects must be approved, we should avoid turning down projects unless health or safety is an issue. The finished project might be a presentation, but it could be many other things. For example a building in Mine Craft, a t-shirt design, a service project for the school or community, a piece of software, a blog, a podcast, or just about anything else.
To get started you should prepare students by explaining that this time is theirs to create, research or build something that they care about. The only requirement is that they use their time effectively. If you would like to assign a grade you would need to set your standards for grading at this time. I personally do not grade these because they rarely relate directly to the core. Remind them that classroom rules apply, and that they need to get a project approved before starting. It's then time to turn them loose.
This is not a time you as a teacher can squeeze in grading a few papers, as you will be a valuable resource in helping to direct them to resources. Please keep in mind that resources are not limited to the internet. There are likely members of the community that work in the area of their project idea. I have heard of amazing interactions between professionals and students. The point is this is a time to think outside the box to help students get the most out of this that they can.
The biggest concern is that we don't have enough time as it is. How do we fit in an hour or two a week for this, when we can't even get through what we need to as it is? The simple answer is that engaged and excited learners learn much faster than disengaged students. I personally believe I can be more successful on core content with this time than without.