Text to Audio File

[Jacob Schmude]

Hi Everyone
Is there a program to convert a text file to a spoken audio file? I'd  
like to make iPod audiobooks out of my book collection, which I  
currently have as straight text files. Is there a program that serves  
this purpose? I know I can use say in a terminal window, but that  
converts to AIFF which takes up a great deal of disk space.

Thanks