SpotLook uses "tracks". Tracks are timelines showing some kind of results, according to their date.
You can use the default tracks or define your own, based on the files UTIs.
Tracks also have a search scope and an attribute to search in (file name, text content or keywords).
You can select some items in each track and quicklook, open or reveal in Finder the items you really want!
Please note that this is an open-source project. Your contributions are certainly welcome.
For now, SpotLook is merely 2000 lines of Objective-C code.
Sorry Tiger users, SpotLook is Leopard only.