I'm a fan of encrypting your hard drive. It's a low impact and simple way to add a layer to your computer's security that doesn't make life harder for the user. But it can be a pain to set up on a fleet of systems as it requires some user intervention along the way. However, some clever folks have found a way to automate the deployment and configuration of FileVault 2.
The process, outlined by Tech Republic, relies on using the command line to issue the appropriate instructions to a Mac. There are some caveats that make me a little wary of the process. For example, each user's username and password is stored in a plain text file on the machine. So, this probably isn't a good idea on a shared system. But for a single user computer, such as a laptop, the risk in minimised as access to the file would require someone already having the appropriate credentials to access the machine.
The process describes processes for recovery keys, adding extra users to the computer and other useful options.
Details of the process, including sample text files and optional commands can be found at Tech Republic.