The TrueCrypt project seems to have deleted the 5.1a source referenced in this article.  The 6.1 source that is now the "stable" source does not compile using the instructions here. 

I suggest ignoring the advice in this and any howto to delete source zip archives ever, if you want to be able to recover at a future time, and carefully backup the materials to rebuild whatever platform you are using.

Since this encrypts your data beyond any recovery, this becomes even more important as you will never decipher this w/o TrueCrypt.  You can of course build up some platform to recover if TrueCrypt is around, but 10 years down the line that may not be the case, so keep a copy around with your encrypted data archive.