Securing a wireless network is easy. And definitely necessary.
You should use WEP at a minimum, but preferably WPA (WPA-PSK).
You should be able to log onto your router, & find the security section, then enable WPA Pre-Shared Key (PSK) & choose a "key" or password. Then, when you connect to the wireless network using your laptop, you simply enter the password (& you can set it to remember it).
You could also use MAC filtering, in addition - you find the MAC address of your laptop's wireless interface, & tell the router to only allow that MAC & no others.
Other things worth doing:
Change the router's SSID from the default, if you haven't already.
Change the router's admin password, if you haven't already. If the password is still the default, someone else could log onto your router's admin & change everything.
There's an article somewhere with info on wireless security.
---------- Post added at 19:56 ---------- Previous post was at 19:56 ----------
And here it is:
http://www.cableforum.co.uk/board/sh...8#post34141478