Originally Posted by Erthbndr
Discbeeper already exists.... Nah I'm good.
You got me all excited for a minute there, I'd done a fair amount of research in the past on RFID systems, but that's an entirely different item, and doesn't seem like something destined to be really practical or something most disc golfers would really want/need. The advantage with RFID is that it is small enough to be able to imbed in in the plastic of the flight plate or can be purchased as sheets of small stickers and would be easy to put on entire disc collection. It's also "Set it and forget it," you'd simply register each sticker serial number in your phone (The MIT students are going the direction of a standalone device with directionfinder as well but would probably cost more) and then forget about it unless you actually need to locate a lost disc. The stickers are about the size of a small price sticker eith a small dot size bump in the middle and a 20 pack was like 2$ or something in bulk for warehouse inventory tracking systems. With the size of a golf disc, could probably imbed a bigger antenna in the flight plate (think the old cell phone antenna booster stickers they sell that you used to stick to the back of the phone or battery) and literally weigh next to nothing.
Discbeeper thing looks like it might be cool for stealth night golf though
You could also pretty much give away stickers to all your regular playing buddies too and even if they didn't have the phone/reader/app you could find their discs for them too since the only thing less fun then looking for your discs is looking for someone else's.