The slingshot guys (myself included) have been running periscope online competitions. If you are unfamiliar with periscope it is an application for your smartphone that broadcasts live video that anyone in the world can see. Because anyone can record a video of a perfect score and post it to youtube, a live video with real people watching and interacting makes the experience that much more intense (nerve wracking). What we do is have the camera ace the target and have a mirror next to the target that is focused on the shooter. Is this something that would interest blowgunners? It is very fun and friendly competition is a motivator to improve!
The best part is that anyone in the world can compete!