Miro is an open source media player which runs on Linux, Mac and Windows. Miro 4 was released a few days ago adding new features like Android sync, Amazon Mp3 Store, Ubuntu AppIndicator, Android store support and lots of other features. Miro Ubuntu PPA was updated yesterday and Miro 4 can now be installed easily.
You can read Miro 4 complete release notes from here
To install Miro 4 in Ubuntu 11.04 Natty / 10.10 Maverick / 10.04 Lucid, open a Terminal and run:
sudo add-apt-repository ppa:pcf/miro-releases
sudo apt-get update
sudo apt-get install miro