MAC address filtering and stopping SSID broadcast just keeps out the neighbour wishing to download his dirty movies from alt.binaries.warez.erotica.asian.multimedia when his wife isn't looking
WEP security depends entirely on the adversary. No ordinary "neighbour" will ever crack WEP. Presently it takes a clever person who needs to be in good reception range for longer than just parking in the lay-by outside, and it is likely to get a lot easier very soon once properly integrated tools appear. Across the road from me is a man whose business is bulk email generation
so no way I would use WEP. But why would anyone bother? If you have secrets then you must use WPA as a minimum. Otherwise, they will just get free internet access, but they can get it 50 yards further down the road with zero effort.
The issue with not using SSID and WPA at the same time applies to quite a few devices, I suspect. A lot of wifi clients can't find the AP if SSID is OFF and encryption (even WEP) is ON. Some will work OK but they need SSID ON for the initial config. One can waste a large chunk of one's life playing with this stuff. If I didn't know the Linksys WPC54G works well I would just head for Ebay and "Cisco" every time. Life's too short.