Used Cisco, Extreme Networks, Foundry, F5, Compaq, Nortel at Network Liquidators

Wifi is everywhere. You can find it at work, in your home, at airports and even the mall. This unwired service has already had a major effect on mobil devices. Everything now seems to be wifi enabled. In fact, T-mobile has released a phone that will hop on to a wifi hotspot if you are in range, and you now have free calling over VOIP. Laptops, PDA, Game systems, and cell phones are starting to come from the factory wifi enabled. The benefits are obvious, broadband internet on the go. Though wifi does have its limitations, namely its short range and slow speeds, but that didn't stop Google. They "wired" the city of Mountain View California for free wifi throughout the entire city. This isn't the only city that's been unwired, several other cities have started building their own municipal wifi network to offer free to anyone with a wifi card.

So with new devices being released every day that make use of open wifi networks, network security becomes ever more important. It's a good idea to take a few steps to secure you're network from unwanted visitors. The first step is changing your SSID (you're network name). Most people leave it on the default settings, which is not secure at all. Most devices will automatically connect to any SSID that is named the same. This is convient if you travel and are connecting to multiple networks. However, this is a major security hole as the devices will connect to any network with that same name. If your network is left at the default setting, say "netgear" anyone who's set their device to reconnect to the SSID of "netgear" will automatically connect to your network. Other than a security threat, if you live in an apartment, you may find that you have several "netgear" SSID's in range of your computer. This will often confuse your wireless card, as it tries to connect to the strongest network.
The second step is to disable SSID broadcasting. This effectively hides your network from anyone who doesn't know your network name. While this isn't fool proof, it's big deterrent to someone that's looking for an easy open network to hop on.
The third step to securing your network is to enable MAC address filtering. Every computer has a unique MAC address, which is like a digital fingerprint. MAC address filtering prevents anyone without an authorized MAC address to log onto your network. While this method again, isn't fool proof and can be compromised, it is again likely the would be intruder will move onto an easier network to log into. I would say it's a safe bet that changing and disabling SSID broadcasting and enabling MAC address filtering would be more than adequate protection for home users.
Now if you want take that extra step and secure your network, the next step would be enabling encryption. First off, I want to say, stay away from WEP encryption if you can. It is by far the weakest encryption for wireless networks, and can be cracked with very little effort. However, some older devices only use WEP, so you may be stuck with it. So if you have to use it, at least follow the previous steps to help minimize your risk of being compromised. There are two other forms of encryption that are very good, WPA and WPA2. Both of these are very good, and are very difficult to crack. I think that WPA has been cracked, but I believe that WPA2 has not. One thing to realize, that enabling encryption will slow down your speed. In fact, many consumer routers cannot even be able to handle WPA2 as it puts a heavy load on the router.