I'm sure this has recently been talked about in another thread but can't find that thread now.
Although you cannot enable this setting you can find which location providers are currently enabled by using the Phone library:
Dim Phone1 As Phone
Dim LocationProvidersAllowed As String
LocationProvidersAllowed = Phone1.GetSettings("location_providers_allowed")
Log(LocationProvidersAllowed)
' LocationProvidersAllowed will be a comma separated list such as gps or network,gps
Martin.