A couple of months ago, I switched to using an Apple MacBook Air as my primary system and I really like it (I have the 13" version, and was moving from the a MacBook Pro). The Macbook Air is a very small, light computer with great battery life and a very nice screen.
Since this switch has driven a few changes in some of my accompanying accessories, I thought I'd share some of the accessories I've found that I really like.
Note: All of the items below are available for other computers - if you don't use a MacBook Air, simply click one of the links below and adjust the search to find one for your computer.
I like my privacy
I spend a lot of time on airplanes, as well as working with my computer in public spaces. For years, I've been a big fan of 3M's privacy filters to keep curious eyes out of my business. When I first switched to the MacBook Air, I ordered one of the 3M privacy filters, but I wasn't happy - the filter fit just fine, but I got this strange moiré pattern on the screen and couldn't stand it, so I ended up returning the filter. I don't like to travel with a "naked" screen, so I continued to do research on this.
I found that 3M makes a specific model number that works with the MacBook Air, as these computers have a higher-res screen than normal notebook computers, and they need a special filter to prevent screen distortion. I ordered one of these higher-resolution filters and I really love it. I also moved from the standard, grey-toned privacy filters I've always used to the newer, gold-toned privacy filter and I think I like the gold ones better.
If you have a MacBook Air, the correct privacy filter will include "…MA…" in the model number - those are the ones specifically for the MacBook Air. You can find the 3M Gold Privacy Filter for the MacBook Air (GPFMA13 for 13" computers, and GPFMA11 for 11" computers) on Amazon. You can also get it in the "normal" grey-tone filter if you don't want the shiny gold effect (PFMA13 for 13" computers, and PFMA11 for 11" computers).
If you haven't seen these in action before, they do a great job of limiting the opportunity to shoulder surf while you're working on your computer. If you look at the computer screen straight-on, you see a normal screen, but as you move to the side, the image becomes unreadable. Be aware- you will have to turn up your brightness a notch or two while using these, as they do absorb some of the light, but I think it is worth it. You can easily remove the screen if you want to allow others to see what is on the screen.
I like to protect my screen
One of the unfortunate drawbacks of using these privacy filters is that they add a bit of thickness to the screen, which can make the screen rub against the keyboard. Over time, this can cause a key-shaped abrasion pattern on the privacy filter, with a buildup of scratches up over time. 
To prevent this, I've always used RadTech's Screensaverz - microfiber screen protection cloths. Not only do they prevent abrasion between the keys and the screen, they also prevent the transfer of finger oil (from the keyboard to the screen), and they double as cleaning cloths.
This is another area where a MacBook Air-specific version of the product makes a big difference. I tried to repurpose my RadTech Screensavrz cloth from my previous computer, but it was too thick for the MacBook Air and prevented the screen from closing fully. You can order the RadTech Screensavrz from Amazon, as well - I got the "Indigo" version.
And, I like to protect the computer itself
One of the main draws for a MacBook Air is its light weight. I decided to try another RadTech product to help protect the computer as I carry it around: RadTech Radsleevz (yeah, I know - funky spelling…) in matching Indigo. Man, was this a good choice. These are extremely thin, and make it easy to hold on to my computer while I carry it around. It is form-fitting for the computer, and adds almost zero bulk to my MacBook Air. That means I can stick it in my bag without taking a lot of room, and its TSA-friendly design means I just drop it in the bin in the interrogation line at the airport.
So, if you're a MacBook Air user like me, I hope this gives you a few ideas on how to travel light while protecting your privacy, your screen, and the pretty silver case of your computer.