The latest build
of Parallels (version 5608) adds some new tools for Linux users. Some of the additions to Parallels Desktop 5608 includes: support for the latest Linux distros, and support for 3D graphics in Windows (running under 10.5.3).
If you are running version 3 of Parallels Desktop, then you are eligible to upgrade for free to Desktop 5608. Just click "Check for Updates" in the Help menu of Parallels.