VoxForge
For those who are wondering about the time commitment required to record a set of prompts I timed myself this last batch.
Using the Audacity method mentioned by Kyle Goetz, I found it took me about 40 minutes to record four of the Phoneme prompt sets (40 prompts in each set.) That included retakes for some prompts that I stumbled on.
It took me maybe another 20 minutes total to prepare and submit the tarballs.
Lets say it can take as little as 15 minutes each prompt set to record and submit.
-joe