This is something I've wanted to add for a long, long time. When working with a project now you have the ability to save the current set of drop downs as a filter.
After providing a name for the filter, it will then show up in the left hand nav:
Filters comprise the entire set of current selections, from bug type, owner, keyword filter, and even the number of issues to show. So as an example, a manager could create a filter for a project's next milestone limited to open issues. This creates a quick way to check project status.
You can download Lighthouse Pro at RIAForge: http://lighthousepro.riaforge.org