Called "One Hundred Paper Cuts", it's aimed at getting rid of small issues with the UI that together end up as a world of pain, hence the name. It's just a special bug reporting tool, but they're looking for specific, system-wide issues that aren't true bugs, but still get in the way of ease of use.
It'll be interesting to see the results. One of the problems with usability is that often what people tell you is the problem isn't really what's wrong. There's a mantra in usability of "Don't ask — observe", and it exists for a very good reason. You'll get a far more accurate picture of what in a UI slows people down by watching them than you will from self-reported systems like this.
This isn't to say One Hundred Paper Cuts is a bad idea; It's not, and I'd even urge you to take part. However, the results will be interesting to read as a study of human behaviour, as well as helping Canonical make Linux more usable.
This article was first posted on ZDNet UK.