Authentic Audiences for Capstones

One of the big knocks on... anything in school... is that it can be artificial and forced (see: Dan Meyer's oeuvre).  You can get around that by removing that wall between the students and the world.  I've had a couple of notable examples of this this year:

• Alex did his now-famous Physics of Osmos analysis, uncovering the accurate (and adjusted) physics behind the game.  This went out all over the web via YouTube and via the contest website.  Also, a cash prize - how's that for relevance?
• Grace's capstone on making vowel sound resonators went live on the Global Physics Department's student capstone project night (recording of the full session is here).  There's a link there to the recording, but she gave a talk about her project to the group of HS and college physics teachers, fielded some questions, and was generally a rock star.

Really, what more could you want for a relevant school experience?  Those are two authentic audiences - folks that really want to know, folks that know what they're listening to, and folks that our students really can speak to and add to the conversation.

Here's the issue - how do we expand this to get more students in on this?  I've made the capstone a bit of a requirement for my AP class this year (needed to get above 90), but I haven't gotten as many as I'd hoped.  I'll keep hammering at it next year, and I think that I can expand it a bit into the regular physics and honors physics classes as well, though there's a very real time consideration with 64 students in all classes vs. 8 students in AP.  It takes time to mentor projects (well, these ran themselves, but if _every_ kid were to do them...).  It's really something worth working towards.

I think that this sort of experience (particularly GPD) is also great to get students in on because it really models the process of revision - we're all teachers, but we're all learning and working and trying to improve, instead of staying static, even though we're "experts."