After upgrading to Ubuntu 10.4 LTS, I was happy to notice that audio in all applications (including Skype) was finally working perfectly! However, I was less happy to notice that Pulseaudio was using quite a lot of CPU-time, and that the sound quality was absolutely awful... So I decided to give OSS4 a try. After some googling, installing a few packages and some minor configuration, OSS4 was up and running, and I must admit the improvement in sound quality is rather significant!