The single biggest complaint I hear from Apple users that have Mac models introduced after 1999 and before 2003 is that Apple canceled production of the AirPort Card. Apple released the original AirPort Card in 1999 and it was more or less the same device through 2004, when it stopped being produced. There's a story behind it that I only have pieces of.
The AirPort Card was a modified version of a PC Card produced originally by Lucent. When Wi-FI was first introduced, there was Intersil and Lucent, and a few other players with very little marketshare. Intersil produced the Prism series of chips used by Linksys and many other companies; Lucent (which acquired its product line by buying WaveLAN) sold its cards under the name Orinoco and sold chips to Apple. Apple included a special slot for this card in iMacs starting in 1999. The original Wi-Fi flavor was 802.11b, which operated at a raw rate of 11 Mbps.
Intersil wound up becoming an also-ran in the Wi-Fi market as upstart Broadcom captured the early 802.11g market despite Intersil pushing the OFDM (Orthogonal Frequency Division Multiplexing) encoding method that became the way that 802.11g reached 54 Mbps of raw speed. Intersil later sold its wireless products to GlobespanVirata which merged with Conexant. Conexant now focuses its wireless efforts on integrated home gateways.
Broadcom grabbed a huge hunk of the 802.11g market, snagging Belkin, Buffalo, Linksys, and Apple. Lucent had, in the meantime, spun its chipmaking division off as Agere, which didn't provide 802.11g chips til a little too late for Apple and the rest of the marketplace. Atheros, meanwhile, which had started as an 802.11a company for the enterprise, shifted gears and signed up NetGear, D-Link, and, later, a lot of startup wireless LAN switch companies. Intel (via Centrino), Marvell, Atheros, and Broadcom are recognized as the leading Wi-Fi chipmakers today.
Apple sold Broadcom's package as a modified mini-PCI card that fits into a new special slot inside all current Macs. It continued to sell the AirPort Card, lowering the price in 2004 to $80 down from the $100 it had charged from its 1999 introduction.
Agere wound up selling its Wi-Fi product line to Proxim which first stopped selling to consumers, and then went into bankruptcy and had its assets acquired by Terabeam, which also acquired the Ricochet brand and system. (Ricochet was an early metropolitan-scale wireless system funded by Paul Allen that could offer speeds up to about 128 Kbps by its end, but like many Allen projects, it was a few years ahead of its time and ahead of the technology.)
It's pretty clear, though I've never heard it said, that at some point in this magical mystery merger tour that whatever company was still produced either the silicon or the complete package for Apple's AirPort Card stopped doing so: either the company's contract with Apple ran out or the company was incapable of continuing to run the product line. Either way, the AirPort Card disappeared and with it the hopes of a short generation of Mac users of having a simple way to connect wirelessly.
Used and never-opened AirPort Cards continue to sell on eBay, now typically for $120 to $140. The problem with used AirPort Cards is that both they and the original AirPort Base Station were notorious for going on the fritz after a year or two. I had two AirPort Base Stations die; this is a fixable problem, however, and the folks at BSR Tech offer repairs for graphite and snow ABS's and newer AirPort Extreme Base Stations, too.
What prompted this reverie is that I noticed on Dealmac today, my favorite bargain-promoting site, an offer for a $100 refurbished AirPort Card from TechRestore.com. Use Dealmac's coupon to get the discount. It's odd to see this card listed as "refurbished" because it's a solid hunk of circuit board. It either works or not. It's possible they did some burn-in tests to confirm that the card works, but that's unclear.
Older Mac owners do have other options that cost under $120 to $140, and even under $100. I wrote a few weeks ago about several options. My favorite, because it's the most flexible and interesting, is the $75 Zyxel AG-225H, a USB 2.0 device that will work with USB 1.1. USB 1.1 is limited to about 12 Mbps, so even though the Zyxel works at 802.11g speeds, pre-USB 2.0 Macs will be limited to about twice what an AirPort Card's throughput would be. (11 Mbps for 802.11b translated to about 5 Mbps of real data flow. The Zyxel should run at full bus speed, however, on USB 1.1.)