VirtualBox keeps on getting better.
Version 3.02 released on July 10th 2009.
Check out the changelog [3]
Links:
[1] http://linux.philosweb.com/drupal/category/it/software/foss
[2] http://linux.philosweb.com/drupal/category/it/virtualization
[3] http://www.virtualbox.org/wiki/Changelog