One of main problems with a mobile laptop cart is that the equipment can be a bit too mobile and "walk out the door." Windows computers have long had software that would call home, so to speak, if they were stolen. The first versions used the modem to dial, but the newer versions wait for an Internet connection. The link below is the first software I've seen for the new Apple laptops.
iAlertU MacBook alarm software available in beta - Engadget