I have a friend with an older G3 Apple notebook who recently had wireless networking setup at her house. Her notebook does not have a wireless adapter though it is Airport ready, which means there’s a built-in antenna and slot for an Airport card. I searched around for a deal on an Airport card and couldn’t find one. Amazingly, these cards cost an average of $120-$150, way too much for a simple card that only provides wireless functionality. The first alternative was a Belkin USB Wireless adapter priced near $40 but according to various postings I had read the performance wasn’t very reliable in OS X and required the adapter be removed before rebooting in order for it to work. I kept searching and came across an alternative that is more reasonably priced (~$75) compared to that of an older model Airport card.
t’s the ZyXEL AG-225H 802.11a/b/g W-Fi Finder and USB adapter. Unlike most of the other USB wireless adapters that work with OS X, this one supports USB 2.0. It functions as a wireless adapter, stand-alone Wi-Fi finder, and even as a wireless access point in conjunction with a computer. For the cost and features it looks like an excellent bargain. It requires OS X 10.3 or higher and will also work on Windows systems.
Another alternative is the Sonnet Aira exterme WiFi (802.11g) Wireless Notebook Card. However, it requires a PCMCIA slot so it won’t work on older iBooks.