A lot of us likes to listen to music on youtube. A great service that helps with that is www.youtube-mp3.org. It allows you to convert videos on youtube that are usually in flv format to much more listener friendly mp3 files. There are competing sites out there that perform the same function as youtube-mp3, but none of them are as good and most of them are spamming multiple pages of ads at you, which youtube-mp3 definitely does not.
Unfortunately its existence is being threatened by Google's lawyers. See this disturbing call for help. I don't think the site could in any possible way be of any harm to Google or their advertising revenue. Instead, Google should be pleased because youtube-mp3 probably saves them a lot of bandwidth as you can relisten to the music without having to download the videos multiple times.
Google has, or had, lots of useful API:s. Such as AppEngine, Google Maps, GMail, Google Docs and many more. But as time goes on, it seems their acceptable use policy for them gets narrower and narrower. First they had a soap api for search which worked exactly like google.com. Then they handicapped it so that it would only return a maximum of about 32 results in a completely different order than what google.com gave. But that wasn't enough so they then replaced it with their totally nerfed custom search api. Apparently they decided that their search results could only be displayed inside correctly google branded search boxes and without any possibility of escaping sponsored results.
Now, if that was the idea all along, then why didn't they start out with those extremely limited usage conditions? Which brings us back to YouTube, which didn't use to have unskippable video ads, sponsored recommendations and overlay video ads. It was all crept upon us. One might counter with that they can do whatever they want with their site, which is true but still seem unfair to me. YouTube would not be very interesting without all the millions of videos created by the users and they are not Google employees. Maybe Google thinks they have reached critical mass and they are now so big that they can implement more restrictions without worrying about a competitor taking over. It may be true unless there is an easy way to transfer videos off youtube and on to another site. But they would never have reached the #1 spot they are at today without the work of millions of users.