Have you ever wondered why the OOTB MOSS search box didn't include the same functionality that the people search provides? If you haven't noticed, the People Search box provides an in-page advanced search experience to easily search by managed properties (i.e. Department, Location, etc.). I've recreated this functionality for the using a CEWP and JavaScript; however, that's not necessarily a scalable solution. As part of my preparation for the upcoming SharePoint Connections conference in Las Vegas, I've started a solution for this on CodePlex. It's functional, but I have more work to do...

http://www.codeplex.com/SPAdvancedSearch
The code and general information is available; however, I haven't created an officially released WSP. Here are some highlights...
This preview release includes:
*Ability to define SharePoint Managed Properties in the advanced search pane using xml
Version 1.0 will be released in mid-to-late October and will include:
*Custom toolpane for defining managed properties (no more xml).
*Automatic display of the advanced search panel via configuration on the toolpane
*Automatic display of the advanced search panel on results pages when a query has been executed
*Removal of managed properties used in the search from the "keyword" input box to improve user experience
Version 1.5 is planned to include these additional features:
*Ability to define a choice list as a value type in the advanced search panel
*Ability to define a lookup list as a value type in the advanced search panel (limited to SharePoint lists)
The advanced search web part derives from the OOTB MOSS Search Box web part so all of the base functionality is available. Once placed on a search entry and / or results page, the web part can be configured to display managed properties of your choice.
http://www.codeplex.com/SPAdvancedSearch