I’ve just released a new version of my Tubecaster application which allows you to download YouTube videos and converts them to MP3. Get it from the Tubecaster homepage.
It was broken for a little while thanks to YouTube changing (or at least changing the access to) their video caching mechanism. When I first created the app in October the Google caching backend site easily allowed you to paste the video id onto the end of a certain URL and returned the video .flv file which I then used Tubecaster to grab and convert, fetch the title from the webpage etc. Now that caching site is unavailable and I had to find a different way to do things.
I found a little script called youtube-dl (link on the Tubecaster homepage) which is a command line utility (also written in Python thank goodness) which really downloads the videos the correct way. It basically creates a proper HTTP request in the same way that the Flash video player does and retrieves the video that way. This means it is far more stable and likely to keep working long-term unless YouTube makes major changes.
This release is pretty basic at this stage, but new features coming soon depending on how much time I can put into it this weekend.