Although there are a few APRS type Balloon launches every few months to serve as educational tools and short-duration small-satellite simulations, there is often not one available when you happen to need to show some students a class.
Now, a Ham in Brazil has written a sound-card decoder for the DAILY National Weather Serice balloons that then takes the balloon data (the fancy ones with GPS) and converts the downlink into APRS format on the ground and then you can feed that into any APRS system or the global APRS internet feed and track these balloons just as if they were APRS balloons.
Since they are throw-aways by the NWS, they are fun to go chase and try to find.
The ham just told me about this, and I encouraged him to package it up, since it has excellent educational value. When he has it all together and posted on line, Ill let everyont know.
This sounds like more fun..
Bob, Wb4APR