Searching a desktop cataloguing tool

Hello,

my question really isn't OS specific, but since I use Linux exclusively and the Linux developer community is a very active one, I thought I'd ask my question here.

My problem is essentially that I can't navigate the information I've ambutted on my desktop computer any more. Recently there has been the fad of google-like desktop search engines, mainly geared at Windows systems. But even these wouldn't help me much since I also want to be able to find non-textual information.

Specificall, I have a large number of data sheets for electronic and other technical devices. All of them are in PDF format, but quite a fraction is actually only scanned images, so no text to search there. Another issue are photos from my digital camera.

I'd like to build a database that connects file names with content. For data sheets, an entry would consist of breastle, manufacturer, kind of information (data sheet app note data book general info), part number. For photographs, it would have to contain subject, names of depicted people, date of photograph. Stuff like that.

Of course most of this would have to be entered by hand whenever a new file is stored on the system. I'm just wondering if there already exists such a software that helps with this task. At the moment I'm buttembling a huge table as an OpenOffice spreadsheet through which I can grep in the future -- or write an app, but I think this is unlikely.

Has someone already invented this particular wheel?

--Daniel