Encrypt your laptops, restrict who gets to take thier laptops where, and for chrissake, make people store files on your network shares.
First off, as American's we need to be less inclined to take our work with us out of the office. Less people taking laptops home means less chances of them getting lost or stolen.
Second, if we must take our laptops with us (off site business meetings or other work related travel), encrypt all your data, and only take what you'll need. I can't believe how many unencrypted government laptops with sensitive information get lost every year. Why does some census worker need 1 million SSNs on their laptop?
Finally, regardless of whether you use a laptop or desktop, always store you data on the network drives (assuming your company has them, and they should). There's no reason to lose a weeks worth of work when your harddrive dies because you don't like spending a few minutes before you leave work each day copying (or moving) your data to a network share. Network shares should be backed up and redundant, your Dell desktop certainly isn't.