For those of you with Android smartphones, there is a free APP in the Google Play Store you can easily find by searching "Zello Walkie Talkie" or "Walkie Talkie". The channel to choose when signing up is "TI99". Give it a try, it might be fun to use on the "TI Weekend".
When setting up it takes a little trial and error to get out of echo mode and into the channel, but you guys are smart enough to figure it out. I'll be hanging around for a few hours (after this post) if you want to try it out.