I was recently asked to deploy Truecrypt 7.1a to 250 computers. We use System Center Configuration Manager, so the simplest way to do this was going to be an .msi. Unfortunately, there is no official MSI for Truecrypt. I found a reference to a 32 bit version, and Richud's instructions on modifying the 32 bit version to install on Windows 7 64 bit.
Here is the compiled Truecrypt 7.1a silent MSI to save others some time. I followed Richud's instructions on modifying the file exactly, using the free MSI editor InstEd.