I tried to get information about available networks using WMI. Unfortunately I always get an empty list. I tried it both via VBScript (using http://www.scriptinternals.com/new/us/support/Internal/WMI%5FMSNdis%5F80211%5FBSSIList.htm) and with Jacob package for Java.
It seems that winmgmts://localhost/root/WMI / MSNdis_80211_BSSIList and MSNdis_80211_WLanBssId are both empty. But Windows lists the available networks in its standard network selection window and I am connected to one of them. It's Vista.
What can I be doing wrong? Are there any other sources for bssid+network strength information?