That "peddling add-ons" thing may work for most of your stuff, Microsoft, but when it comes to paying US$90/AU$150 for a wi-fi adapter, the argument gets a little shaky.
The PS3 has built-in wi-fi. The Wii has it. The PSP has it. Heck, even the DS has it, making the prospect of spending US$90/AU$150 on Microsoft's "add-on" as surprising as it is ridiculous.
But there's a way around it. A few ways, in fact. All of them involve buying routers or third-party adapters, and all involve more fiddling around than the official solution's plug-n-play, but does that matter? Every time you look at the setup hassles and baulk at the process, try and remember you'll baulk more at paying US$90/AU$150 for a wi-fi adapter.
Full, handy, helpful guide below.