I've done quite a bit of iBeacon stuff including emulating them with Raspberry Pi's and writing an iOS app that measures the OS behavior against iBeacons. It's pretty interesting stuff, there are a couple of my beacon's I'm using to test iOS behaviors with that are buried in a New York city park near my place.

If you find one let me know.

I suppose I could write some of my findings up but I've been a bit busy...