Very helpful reference URL:http://www.rockbox.org/twiki/bin/view/Main/ZIFToATAAdapter
I finally got a ZIF adapter to work with my Gigabeat F40. ZIF adapter purchased here:http://www.dealextreme.com/details.dx/sku.10887
I'm adding this new topic because I actually tried this a few months back, and could not get it to work. What I found out later was that the first adapter I received from DealExtreme was, in fact, a dud. I purchased a second one after reading the reference URL and, lo and behold, the new one works, no errors! I'm using a Toshiba laptop HD (MK6008GAH) for my testing, btw. Happily running Rockbox on it.
So, if you are planning to do this yourself, I would recommend buying at least two adapters.
EDIT: I had a big issue putting it back together (would keep turning off). what a realized is that the leads connecting into the HD were a bit exposed on my cable, and were touching the HD metal and shorting out, when pressed together. A bit of electical tape did the trick - or, reducing the size of the leads with a razorblade might also work).