Are there any commercially available USB flash drives that offer additional security?

To do that, either the security would be baked into the silicon, or would have to be in a separate (hidden?) partition on the USB drive.

They definitely exist. http://www.ironprotector.com/?gclid=CPj6-6fMo8YCFUhgfgodnBACJg
for example, but dozens more.

I don’t know that a secure USB’ like the ones above are notably better than doing good encryption on a regular USB drive.

The Sandisc Cruiser Slide series have a vault feature where you can password the drive to prevent the opportunist from getting to your data. I have some of those and I like them, (but that is just me).

BitLocker To Go.

No real need for special hardware.

The same can be done on OS X or Linux too.

@johnpowell do you know if Bitlocker has a version for Windows 8?

Sigh..

BitLocker and BitLocker To Go require Windows 8 Pro or Enterprise.

That is a bit of a bummer.

If you just have Windows Home 8.1 or whatever you might want to look into forks of truecrypt. I can’t vouch for any of them so I won’t recommend one.

I go for software solutions myself. Despite the hubbub surrounding the sudden cessation of development, the standard is still TrueCrypt 7.1a.

Any cautionary messages you may hear about TrueCrypt are simply a result of the developer’s covering their ass just in case a flaw is found in the last version they did before quitting simply because they will not fix them. However, the independent security audits of TrueCrypt have yet to find any weaknesses anyways, and it’s strong enough that the NSA isn’t exactly pleased, so I still trust it. I cannot say the same for it’s forks, CipherShed or VeraCrypt.

BitLocker is strictly for the Ultimate and Enterprise versions of Vista and Win7, and the Pro and Ultimate versions of Win8. Most Win7 computers run Home Premium while Win8 is mostly the regular version, thus most lack BitLocker functionality, and BitLocker doesn’t work with OS X or Linux while TrueCrypt does.