This is a “why didn’t I think of that?” idea. [Alec] needed a way to connect an IDE DVD drive using USB. Rather than order a connector he pulled the circuit board out of an old USB hard drive enclosure and connected to his DVD drive. Bang, recognized and running.
This will prove extremely handy if you have a netbook without an optical drive. We’ve used Unetbootin to move Linux ISO images to a thumb drive in the past. In addition to getting around the lack of an optical drive, this saves burning the data to a piece of plastic. But, you should be able to use this with a Leopard retail DVD instead of a 16GB thumb drive for a Hackintosh conversion. That means you could install Leopard on a netbook without needing a Mac to transfer the disk image to your thumb drive first.