Finished! With 10 hours to spare!
Please view full on all, compression really destroys mosaics.
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I tried doing the tiles a few different ways: I made a "master tile" in photoshop and cloned that, switching directions for variation. Once I realised how time consuming that would be to finish this in time, I hand-tiled the rest, but I think now that it looks more like something by Tiffany. Oh, well.

I wrote a tutorial how to create that.
You can check it here.
http://www.photoshoptalent.com/photoshop-tutorials/mosaic-effect-without-filters.php

Fun project. My first mosaic. :)