Ideas for securing a MacBook Air? I am in the market for a new laptop and have my eye on the new MacBook Air (13" model). It's perfect in every way, except one. Unlike the white MacBook (RIP) and MacBook Pros, the Air lacks a Kensington lock slot. I spend a great deal of time in cafes and don't like worrying about my laptop while I'm going to the restroom or standing in line to get a refill, etc.

Do you have any ideas for securing the MacBook Air for use in a public area? I haven't found other options that I find satisfactory.

I understand the Kensington cable lock isn't a perfectly secure system. (What is?) But it's been enough of a deterrent that I've never had even a concern using my current MacBook in cafes since I got it in 2006. Whereas other friends have had their unsecured, unattended laptops stolen while working in local cafes, I've never had even a hint of a problem while using the cable lock on my MacBook.

Note: Services like Prey Project are great, and I'm signed up for the service, but I'm searching in particular for a deterrent that will make it so that I don't have to ever actually call upon the service.
It is so light, I just rarely need to leave it unsupervised. I'll hand it to the staff to set behind the counter if I need to leave to feed a meter or use the facilities on the rare occasion when I don't have a shoulder bag. 

They are so light and thin, it's not a hassle carrying it. 

If you must, audible alarms that plug into USB ports are available, but who wants to be the guy with the alarm going off unintentionally? Not recommended. 

I would bet Kensington comes out with a leash that goes around the display hinge and tightens before college starts in the fall.