It's called Enounce Myspeed. I personally use the regular $30 version of MySpeed for Windows, but there's a 7-day free trial of MySpeed Premier ($100) at that link, after which you'd need to register to continue using it. It's a good way to see if this is something you'd be interested in buying.
Staniel over on depoman.com has taken this concept to a new level and has created some videos of his song and podcast practice which can be found on here. Happy practicing, and keep changing up the practice routine to keep things spicy and fresh. (Hmm, I must be hungry.)
This is just a tool I find useful for practicing videos or other flash-based audio or video at multiple speed levels, like the practice tracks found on some web-based dictation libraries (like StenoU) or videos on YouTube. I'm not getting a thing for promoting this program, just think it's worthwhile to share.
Here are some video depositions that would be great to practice to:
Cindy Anthony Deposition Part 1
Joe Cruz Deposition
Bill Gates Deposition Part 1
And then I can't resist. Once you have your practice in, check out these nightmare/funny depositions for a laugh. Caution: some coarse language
Best Deposition Ever
What Not to Do During a Deposition
I Don't Recall