Ebrown p ff you are unlucky enough to get the government interested enough to use NSA level of assets on you, you are in a world of hurt in any case.
A van with a few million dollars of electronic park in your neighborhood or breaking in and placing a hardware/software key logger in your computers systems would be just the start.
For most of us the risk model is having the computer stolen as over 600,000 laptops are every year at our airports for example and even a bio hardware drive lock turn on should deal with that threat very nicely less alone truecrypt.
Second common threat is taking the computer in for some form of repair If you do not think that the technicians is not going to be looking to at the very least to copy your music and your porn you are living in a dream world. With some chance they will also be looking for credit cards and bank passwords.
The last time I did needed to take a computer in for some work on boot up the computer ask for a pass phrase to open a volume on my drive and the technician then ask me what this was about. I told him with a smile that is where I kept my music and porn collection that I do not wish to share with the Greek squad<grin>.
The very worst case for most of us is that for some reason local law enforcement would get interest enough to seize our computer systems and in that case pgp and truecrypt once more would be enough to deal with that level of threat a few hundred times over.