I used to take noise toy boards similar to that (uses an ISD1000 or ISD1020 20 second recording chip) and convert them by adding parts to them to make Off-The-Air Digital Voice Recorders (DVR) or "Watergates". Back in the mid to late 90's. I even "dead bug" the chips by themselves and added the components directly to the pins. I still have a few samples laying around. Fun to play with, you could record other people and fire it back at them, or save it for later to fire at someone else. I was the one making digital recorders in North East Ohio back then. I would go to the Radio Shack stores nearby and buy up all of their ISD1000 stock. I also used any other chip recorder, like the MemoMate keyfob, had 2 buttons on it, one for record, one for playback. The devices I made automatically keyed the radio when I pressed the Play button, holding it in Transmit, and unkeyed when the recording was finished. No need to key the mic PTT, it did it by itself. I also had the Record line tapping the Squelch gate, where you set the Squelch, and pressed the Record button, when the Squelch opened up, when someone else keyed up, it would start recording from that point until they unkeyed.
I had one installed in one of my PC122's (not the one I currently have), and while picking up friends and waiting in the car to go to the Cleveland OH Zoo, I caught a perfect recording of someone asking "Uh, Breaker 19 for a Radio Check!". I used to live near The Ohio Turnpike, I-80, and there is a 2 lane highway that runs parallel with I-80 there, Rt 303. On the way to Cleveland, I fired that recording over and over, pausing between transmissions, so truckers (mostly) would come back to my recording. The truckers were getting pissed, thinking I was on I-80, which truck I was in, or maybe it is that pickup truck pulling a lawnmower trailer? Or maybe it was that JB Hunt driver? Or that station wagon? "Which direction is he going?" "Yeah, he's going West, I've heard him the past 5 miles". Wanted me (or whomever was doing that), to stop at the next plaza for a fight.
One other time, I had another recorder in one of my RCI-2950's, and I had just pulled into my driveway and was about to get out of my car, when I heard the most awful bleedover noise I had ever heard, I found it, some guy in a pickup truck had just drove by, and was playing some song by Elvis, microphone up to the speaker in the dash, severely overmodulated as all get out. So, I recorded 20 seconds of that mess, when he unkeyed, I fired it right back at him. He responded "Hey, who is that with the same Elvis music I was playing?", I recorded him, fired that right back at him, he was talking to recordings of himself, unaware that he was being recorded and played back at him. He had a whole 5 minute conversation, answering his previous recordings, before he finally got a little out of range, and asked his wife in the car behind him, if she had heard all that, she replied, sounded like you were talking to yourself.
;-)
