Update to the js photo filters: you can now Shift-click any photo on this site multiple times for 90°, 180° and 270° rotation. Wheee!
How it's done:
someElement.style.filter = 'progid:DXImageTransform.Microsoft.BasicImage(rotation=1)'; //or 2, or 3
Here's an image to test it on:
And: it now also works for images in the forum. Useful when viewing the Upside-down photos.
Because when you rotate them, you've a nice square and not a rectangle (the original format of the image)