Is there an equivalent to the Mac's terminal command "say" in Ubuntu 9.10?
espeak should be installed by default as text-to-speech engine on Linux.
You should be able to get it to speak from command-line by doing something like this:
echo "Text to speak"|espeak
You can also start espeak by just entering
espeak itself, and then enter each line of text you want spoken followed by enter.
Other TTS engines for Linux you could look at:
Espeak is available at (but should be installed by default!):