Skype 2.1 beta an open source UI layer and works great one pulse audio in karmic.

Enable medibuntu :

sudo wget http://www.medibuntu.org/sources.list.d/$(lsb_release -cs).list --output-document=/etc/apt/sources.list.d/medibuntu.list && sudo apt-get -q update && sudo apt-get --yes -q --allow-unauthenticated install medibuntu-keyring && sudo apt-get -q update

Install skype:

sudo aptitude install skype-static-oss skype

Done enjoy Skype!