Take a look at Media Pro. It can catalog:
image files,
audio files,
video files,
text files (Word, Excel, Powerpoint, text),
PDF files,
fonts,
HTML files, Illustration files (Adobe illustrator, CorelDraw, Canvas, PowerCadd, Appleworks)
Publishing files (Word, Indesign, PageMaker, QuarkExpress, AppleWorks, etc.).
You can have multiple catalogs and be able to search over all of them with the results displayed in a new, temporary catalog. It uses keywords and hierarchical keywords, catalog sets (Events in iPhoto), Supplemental catefories (Albums) and so much more.
It's designed so you can have the catalogs on one Mac or drive and the cataloged files on other volumes/hard drives - even CD/DVDs.
OT