My first purchase was the "Click-n-Dig" brand, which is very nice. It has both stick-on and keyring style beepers, check. It comes with spare batteries for all compents, nice. However, the beepers are relatively large. In our case they are actually bigger than both the cell phone and the remote. And the dongle with the buttons to make the beepers beep is tiny; they've gone to a lot of trouble to make the colors and shapes of the buttons match the colors and shapes of the beepers, but there's no way to distinguish which beeper you've assigned to which object except to keep a separate list. Also, the battery covers have fallen right off of both the keychain beepers in the 4-beeper set that I got, and so far I've only found one.
http://www.amazon.com/Click-Receivers-Wireless-Keyfinder-Batteries/dp/B009JJJ7S4/
This Sharper Image one has a remote with spaces where you can write what each beeper was attached to, but the beepers are gigantic and the device apparently suffers from Sharper Image's reliability issues.
http://www.amazon.com/Sharper-Image-Wireless-Electronic-SI667GRY/dp/B0000A1OCM
This "EZ-Find" device seems to have it all; mini stick-on beepers, a way to select a beeper by assigned name, but the form function of the remote is just painful and absurd. I'm trying to like it, but I don't think that I can. Plus it has a price befitting such a complicated piece of electronics.
http://www.amazon.com/EZ-FIND-Item-Design-Electronic-Locator/dp/B004FVFGMW/
http://ez-find.com/faqs/
More as new developments arise.
Some asides:
This is an interesting idea using rfid tags, but it turns out to be pure vaporous concept and unlikely to ever actually exist:
http://www.yankodesign.com/2011/11/03/key-control/
Here's a version of the Click-n-Dig that has even more oversized beepers, plus the remote is huge:
http://www.amazon.com/Smart-Find-Remote-Control-Locator/dp/B0000X0YTO/
This "Find One Find All" concept is pretty neat, but the smallest stick-on remote that they have is the size of a credit card:
http://www.findonefindall.com/
