Yes, I encrypt literally everything I have that can be encrypted, external drives too.
FileVault2, TrueCrypt, DiskCryptor, EncFS, dm-crypt/luks I use/have used all of these, depending on what the system is (FileVault2 for OS X, TrueCrypt/DiskCryptor for Windows, dm-crypt/luks for Linux/BSD, etc)
I also don't store anything in the cloud unless the file is inside an encrypted container, in case of DropBox, I used to use BoxCryptor (basically a GUI wrapper for EncFS for Windows/OS X)
I do all this so I'm not worried about my data being accessed if my computers are lost or stolen, because everything is encrypted.
Tinfoil hat mode? Maybe, but if I have the option to protect my data, why shouldn't I do it?