I was wondering if any of the gerbils with RF engineering experience could explain something I've been curious about.
Over the past few years, a number of very small USB WiFi adapters have come on the market, where the entire adapter basically fits inside the USB connector. How the heck do you fit an effective antenna inside something that tiny? Compounding the matter, the antenna is located right next to a significant source of EMI!
Even cheap-ass ones (like this one) seem to work on par with -- if not better than -- the WiFi adapters built in to many laptops from just a few years ago. I've "upgraded" the WiFi on several laptops with these things (both the linked brand and "Edimax"), and I continue to be amazed by the bang for the buck you get. (They're also a cheap and easy fix for laptop WiFi adapters that don't play nice with Linux...)