The new MacBook Air doesn't include an Ethernet port and there are times that it comes really handy. Maybe at the office or just at the hotel you can find an Ethernet plug and then you remember that your ultrathin portable computer lacks it. Apple offers a solution with an adapter that sells por $29 plus shipping and taxes. Here in Europe you must pay 29 € plus 8.85 € shipping, resulting in a total of 37.85 €. This is more than $51... just incredible. http://store.apple.com/us/product/MC704ZM/A?fnode=MTY1NDA3Ng&mco=MTk0MjUyNTE But luckily there's another option: go to eBay and buy a compatible product. That's what I have made and once again the price difference is outstanding. I got it shipped including VAT and taxes for a mere 8,28 €, that is around $11. Externally there are no big differences. Better quality plastics for sure in the Apple model, including a gorgeous Apple logo, ... but this doesn't justify the price difference. Here in Europe this price difference is more than a 462%. But differences do not end here. The Apple device is compatible with Mac OS X and looking up the Q&A in its store web page, it doesn't work with Windows (more info here). and this means that if you use Windows natively with Bootcamp you won't be able to use it (it's not the case with VMWare because Ethernet is virtualized). The compatible model includes drivers for every version of Windows, Mac OS X, FreeBSD and even Windows CE... You will get WHQL signed Windows drivers, 32 or 64 bits. That's a huge difference. After a week of placing the order, I've received it perfectly protected. And this is the drivers CD. I don't like CDs because they're likely to be outdated. Instead I prefer going online to the manufacturer web page and check if there are newer ones. This is the case with the Moschip MCS7830 unit. You can download all the drivers and product documentation at http://www.moschip.com/mcs7830_downloads.php. It requires registering but it's easy. Once downloaded, you can verify that they run smoothly with your MacBook Air. Here's mine, next to the other two options that I use regularly: the included Airport Wi-Fi adapter and my iPhone 4 in tethering mode. This is another test in a different machine running Windows 7 And this is the detail offered by Mac OS X System Profiler. Sorry about the information being in spanish. In the USA you can get a similar product at http://cgi.ebay.com/USB-2-0-Ethernet-10-100Mbps-RJ45-LAN-Adapter-Mac-OS-X-/170581229990 for $6.5 plus $2.99 shipping. The best place to store this adapter is plugged with your Ethernet cable. You will never missed one or the other when you need both.