I was browsing Google Images and found yet another keyboard remotely similar to Microsoft Natural or Apple Adjustable keyboards.
It's called Acer Ergo 61 or Future Keyboard (Ergo or JVPERGO on the sticker), and it's fixed-split with 75% layout (including Windows keys), circular touchpad (Synaptics) in the middle, wrist rests and a separate numpad. Quite interesting among all those uninspired MS Natural clones. Announced in 1999/2000.
Random review:
Dan's Data