Hasn't this been around for a while?

http://www.silverstonetek.com/products/p_contents.php?pno=HDDBOOST&area=

"HDDBOOST" looks to offer something similar by combining the HD/SSD yourself. I was tempted by one of these a few months back just out of curiosity!

Not a modern myth (this actually happened to me)

Back when I was writing and supporting an old COBOL green-screen app, I had the following call.

"I can't find the 'any' key."

I had to explain to the bemused user (without laughing) that she could in fact press any of the keys on her keyboard.

God's honest truth - it REALLY happened!