I know what you mean, i'm always thinking someone may be looking at what i'm doing on the net, mine pics up 4 other networks aswell, so if i can see 4 other peoples networks they can see me!!

i have a rangemax router set to wpa2 [although i have no idea what it means just it's more secure] but there is a setting somewhere on your router login settings page that lets you set it to just allow your laptop to connect, it says the MAC address of your laptop which i think simply means it will only allow your laptop connect to the router.