There is so much tweaking you can do to MOSS's results, that a broad enough title didn't do enough justice to MOSS search's flexibility.

So, here is a restrictive title, but a rather cool but specific trick you can do with MOSS 2007 search.

Under shared services, go to search settings. Under there you would see "Metadata property mappings". Under there, you would see a number of "Managed Properties" already setup for you. You could add your own if you wanted to by clicking on the "New Managed Property" button above.

These Managed properties can be used in search scopes - and that is a very very powerful concept. Say for instance, if you wanted to search over all the "Word documents" on your local sharepoint sites - how would you do that?

Well, it's pretty simple.

1. As you can see, there is already a Managed Property called "FileExtension". If there wasn't - you could create your own.
2. Next, click on that Managed Property, and there is a checkbox at the bottom that says - "Allow this property to be used in scopes" <-- Check that bad boy.
3. Go back to search scopes, and create a new search scope called "Word Documents".
4. Add the following rule to "Word documents" –

5. Great, now run a full crawl on the "Local SharePoint Sites" content source (or whatever content source you are using).
6. Update the search scopes
7. Make this new search scope available for searching on your site.
8. And, If you just shook your head at the last 3 steps, I have covered them at numerous places on my blog. 
9. Now issue a search on "Word Documents" -
10. You just created a search engine to search over word documents only. Now check this out - throw in an iFilter for PDF, and index a fileshare location, and you got a search engine for PDF files that live on \\DesignerFolks\GuysWhoMoveIntoSharePoint\*.pdf. 

This gets ESPECIALLY powerful with BDC search. BDC will let you create new crawled properties, and you can then map them to managed properties, and slice and dice LOB data in any form you want - through a search engine.