bgscan? Can I scan while not connected to a network?

[Ed W]

Hi, would it be possible for the sample config to list the bgscan param 
for wpa_supplicant and sensible parameters for it please?

In particular I have a question about where it can be placed.  Can it 
only be placed into a network definition?  How might I configure 
wpa_supplicant to maintain an updated list of available networks in the 
situation it's not connected to any current network?

Also is the "smarter" bgscan ready for real use?

Thanks

Ed W