Mountable encrypted file? What to use?

[Greg Morell]

Since TrueCrypt doesn't work on FreeBSD, I'm wondering what you'd recommend for this:

I like to keep all of my sensitive stuff in a few encrypted mountable files.

Something where I can copy the file to a USB key for backup, but not worry if I lose the USB key since it's just an encrypted file.  But when on a computer, I can mount it as a volume.

On OS X, I use encrypted 'dmg' volumes.

On Linux and Windows, I use TrueCrypt.

What should I use on FreeBSD?

It doesn't have to be portable.  Something FreeBSD-only is fine.

Thanks!