[Amicius]

I think something that could draw in a LOT of people -- and be an awesome STEM tool -- would be non-cost-prohibitive VHF and UHF SDR radios that can be easily controlled wirelessly (Bluetooth, WiFi, or both) and allow for any number of modulations from standard FM as is used on 2m/70cm, analog slow-scan TV, digital TV, digital voice, data and more. Heck, the creation of a handshake protocol that starts as AX.25 and the stations identify a switch-to protocol would be great, and since it's digital and we're assuming SDR, that handshake could be "Oh, you don't have the ABC123XYZ codec? I'll send it to you now!" Yes... trusting a CODEC from an unverified source could be dangerous but that's part of the fun of experimentation!

[AWildC182]

I think such things are coming very soon. VHF in particular is really easy to design for as the direct sampling SDR components supporting that band can be had cheaply. You can go on digikey.com right now and spec out a pretty nice pipeline without too much difficulty.