Connecting to a Wireless LAN with Linux, Part 1
The Hardware Hokey-Pokey
Wireless hardware for Linux is a moving target. The wireless network adapter that worked fine with Linux yesterday may be released with an unsupported radio chipset today, and with no indication of the change. So buyer beware--always confirm the chipset before you buy. The good news is a lot of wireless adapters have native Linux support, and for those that don't, the NdisWrapper utility lets you use the Windows drivers on your Linux box.
The adapters to look for are based on Prism radio chipsets. The 802.11b chipsets are best-supported and easiest to use; drivers are included in the Linux kernel, and they should work out of the box if you selected the right package group--usually "laptop"--at installation.
There are Linux drivers and utilities for CiscoAironet 350 adapters, which are available for download from Cisco's Web site (see Resources), and are also built into the kernel.
Intel has recently released Linux drivers for Centrino. Centrino support is still rather beta, so stay tuned for improvements. The word "Centrino" is a marketing label; only laptops equipped with an Intel processor, Intel chipset and an Intel PRO/Wireless 2100 adapter can carry the Centrino label. The PRO/Wireless 2100 is not available separately.
Ralink (see Resources) appears to offer enthusiastic Linux support, though their drivers are still beta. I have not tried these, so reports from actual real-life users are welcome.
Be sure to consult the links in Resources for specific cards. Because even when a particular adapter uses a Prism radio chipset, it may have unsupported firmware or other modifications. Jean Tourrilhes' site "Wireless LAN resources for Linux" is the ultimate resource for Linux users.