This might be the time for a new idea (beware!;)
As you can see on the upload page, it gets quite crowded and loads very slow. And we only have a few images up there.
So, there are some mechanisms we could try to clean this up and fix the unwanted uploads issue: 1. Create subdirectories for categories ("biology" etc.) 2. Create SourceForge-style subdirectories, by the first and the first two letters. "foobar.jpg" would go to "f/fo/foobar.jpg". 3. Create a binary namespace.
Personally, I'd vote for #2. We won't have to create a category scheme (as in #1), and the tech would be easy (in contrast to #2). It would also group images quite efficiently.
Now, what I had in mind was this: The current way of linking to images is fine (just type in the URL!), but *additionally*, we could have another scheme for linking wikipedia-internal images. Example: "{{IMG:foobar.jpg}}". Now, the software could automatically determine the correct URL, based on the storage scheme. It would also enable us to find unlinked images quite easily.
An additional advantage could be tha ability to cope with new data types. I think of SVG, as an example. The code for including such a file is quite different, but for the user, it would be the same as a jpg ("{{IMG:foobar.svg}}").
Just dumping my random thoughts on you, Magnus