Thank you so much for this enablement! I've been thinking about that very solution -- not the multimedia one in particular, but a sketchbook. It might combine some of the best aspects of another spiral notebook I liked (the Mnemosyne) with thick enough paper to handle the brush pens and fountain pens I like.

it also would be a good lay-flat notebook; I did get a Fabriano sketchbook that was my "all in one" notebook, but the fact that it doesn't stay open gets annoying.

In terms of decoration, though, why not just collage the cover? Or stick a clear envelope on it and rotate decorative pieces through it? You mentioned those magnetic bookmarks; even just paperclips would hold some king of cover, I should think.

The inspiration is much appreciated!