There is a very easy fix - set-up your Laptop to boot from USB and never touch the laptop drive. Most current Laptops will allow this without a problem and your laptop drive will be perfectly clean.

Not only that, forget the laptop and just take the USB stick with you. You can plug it into almost any PC / Laptop (with a generic FreeBSD / Linux kernel on the USB drive) and take your 'system' with you in your pocket. 16 and 32GB drives are much cheaper than a laptop :]

There is one down side however, the boot time is a bit longer - but if you are worried about your data, a longer boot up is a minor issue.