Use truecrypt to make data unrecoverable
The other day I was thinking, and I looked up this question because I was pretty sure a question similar to this had been asked. (I had never heard of that method previously, but anyways...) Would it be an acceptable alternative to encrypt a whole volume with a program such as TrueCrypt with an extremely strong encryption key and algorithm, then format the disk? TrueCrypt is pretty strong by its self, and by the time you plug in that disk and say, install an OS on it, vital parts of the data that were previously there (keep in mind, it was encrypted, then formatted, then overwritten with a new OS in parts) are gone - which would effectively make it impossible (correct me if wrong, please) to recover said volume - Would this be another method to securely erasing a HDD?
*Note: Tried to add format tag, doesn't exist... need 300 rep to make it =p