For many people, a laptop is the heart and soul of business; it's the primary tool of those who work on the road, at home or otherwise away from the office. While losing a laptop can be costly in and of itself, the cost is even greater when the laptop contains important or sensitive data. Preventing your laptop from being lost or stolen is mainly achieved through vigilance, but you can get a lock for it as well. You should also incorporate some ways of securing your data (such as encryption and tracking software) in the case that first line of defense fails.
Always have a way to constantly track your laptop's location. You can't guarantee its safety unless it's within your vision, and it's preferable to have at least one hand on it at all times when in public places. Don't leave it in your car when you need to stop for a quick errand or on a table when you go to pick up a drink. You can get locks to attach it to a table or some other piece of furniture, but if the laptop is locked to anything that could conceivably be moved, it could still be unsafe.
All of us are prone to letting our guard down on one occasion or another, and in these cases it's important to have backup measures in place. First, decentralize your data; every week or so, back up the most important information on your laptop to a secure desktop computer or an external hard drive. Next, look into laptop hard drive encryption so that sensitive information won't be in danger of falling into the wrong hands if it's stolen. Finally, there is software available that can find your laptop's physical location if it later connects to the Internet, but this is a last resort, and not to be relied upon without taking other preventative measures first.