IEEE 802.11 and its derived wireless LAN technologies are probably the most often used networking technology for constructing your wireless LAN. The technology uses DSSS ( Direct Sequence Spread Spectrum ) to generate the bitstreams to be transferred in the 2.45-GHz ISM band with a speed up to 11 Mbps.
There are two types of attacks. One is simply use of the broadcasting property of wireless technology to further penetrate a random wireless LAN. The 2nd is related to the vulnerabilities in the WEP ( wired Equivalent Privacy).

War driving or the so called parking-lot attack is the most trivial method used today. Tools used are a laptop, a wireless card, an extention attenna, and programs like AiroPeek and Sniffer Wireless. The first step in sniffing for the service set idenifier ( SSID ). Useing the SSID to gain access to the wireless LAN possibly through a DHCP-assigned IP address. useing restrictions to only certain MAC addresses is not enough, for addresses can be spoofed.

Standard access control mechanisms (such as SSID and MAC address restrictions) still need to be adopted, but to futher protect your corp. an internal firewall and security protocol like IPSec should be implemented.

WEP Countermeasure
Dont wait for a revised WEP specification to be completed and implemented by your wireless vendor. Deploy any of the following technologies to combat the potential WEP brute force attack: VPN, IPSec, SSL, SSH, and Kerberos. Port based network access control will be used to help, if not to substitute for, WEP in a wireless network authentication and authorization mechanisms in the future.

If you have anything to add to this post feel free links would be nice to see too.
Books for futher research inlcude 802.11 wireless security, Microsoft w2k pro, and hacking exposed. also check with the pringles company. LOL