The MacBook Air has no Kensington lock slot. What other options are available for protecting it from theft?
Plugspy by Celmaro claims to secure a MacBook Air by monitoring its MagSafe connection status:
Plug Spy auto activates when your screen is locked and start an annoying high volume alert sound and send a Growl notification when your MacBook gets unplugged from the MagSafe power adapter.
Here's one USB option. Haven't tested it personally, though, but seems better than some of the alternatives involving plastic shells and such.
I like a good old hardware solution, just a basic lock/ case. I ordered the below macbook air lock. It worked! the bottom part has a built in security lock and you get a cable with it.