The subject of wireless security comes up a lot in discussions and it is interesting to see that more networks have security but it is still only about 50%. Here are some wardrives* that I have done over the last couple years from 10/11/05 to 01/16/07
The Green names are open, red are using WEP and Purple are using WPA. You should be using WPA with a long complicated password. If you think that annoying 128bit hex key for WEP is secure I suggest you watch this video
If you want a cool way to view my latest wardrive download this file test.kml and it will open in Google Earth. Another interesting file for you is found here Kismac Google Earth Plugin. This will let you view networks that people have uploaded for your area.
*Just a note, there has been some arrests and legal action regarding wardriving lately. These networks were found with my network card in passive mode so in no way were they accessed by me. It is not illegal to listen.