I vote TrueCrypt for Full Disk and Container based encryption. If you have a newer i5 or i7 system AES-INI is built into the Intel CPU itself which makes TrueCrypt achieve GREAT encryption/decryption speeds... I don't recommend using TrueCrypt or any full-disk encryption suite on a computer you use to edit HD video. I recommend having 2 computers... one "dirty" and one "clean". Another way you can achieve this is to install a Windows Virtual Machine inside of a encrypted container... that way once you dismount the encrypted container, there is not much left over. Or have 2 physical CPU's on a KVM switch. Don't forget to always lock the screen on the secure computer when you walk away.
One threat you have to be weary about is KEYLOGGERS. I've used them to great success that's why I'm so paranoid of them. The trick is not to try to break somebodies encryption set-up, but to bypass it: obtain their passphrase (password but at-least a sentence long).
I myself, built a custom highly secure laptop. It's made from a sub $500 laptop in the event of hardware failure... I would be unable to ever open it again.... most people say BUT WHAT IF A FAN GOES OUT?
I'd rather a fan fail and have to image my hard drive to another sub $500 laptop rather then somebody physically tamper with the hardware without leaving telltale signs behind.... are you fighting off your wife or a hostile foreign intelligence agency...
Don't forget to always use Firefox and run it in a sand-boxing application such as:
http://www.sandboxie.com/ to prevent unknown threats being used to exploit your operating system.
If you're using public wifi/hotel I also suggest a VPN account to route your traffic to a secure 3rd party to prevent local traffic analysis of your internet traffic:
http://www.prq.se/?p=tunnel&intl=1