Where does OS X remember previously connected bluetooth devices? I completely erased my hard drive (DOE compliant 3 pass secure erase) that had OS X Lion on it and reinstalled it from the recovery drive earlier today. To my astonishment, I saw that the Bluetooth preferences remembered all my 4 previously paired devices, albeit, with only their MAC addresses and not device names.



Where is this information stored? I did not reset my PRAM, but this page does not indicate that it keeps a history of Bluetooth devices connected. 

What other similar information is stored persistently? My networks preferences didn't show any of my previously connected wireless networks, but I'm curious now — is it possible to retrieve it after such a wipe and reinstall?
There's a question from SuperUser that might be useful for you.

In Lion, Bluetooth information is stored in different .plist file with Bluetooth prefix. For my case, I have~/Library/Preferences/com.apple.BluetoothAudioAgent.plist and ~/Library/Preferences/com.apple.BluetoothFileExchange.plist