WINNER, WINNER, CHICKEN DINNER!!!
Worth their weight in gold!  Not really, but well worth the 10 bucks or so.  They work really well, keep my glasses from getting scratched, and glasses won't fall out when leaning over like they do from a shirt pocket.  The magnets are so strong that there is never any danger of it falling off my shirt, yet it is easy to position once you get the hang of it.  While wearing your shirt, install the holder approximately where you want it to be, pull your shirt tight with one hand, then simply slide the holder to exactly where you want it.  It won't move again until YOU move it.  SOOOOO much better than using granny chains, croakies, etc.
Rating: 5 stars