for uh...flashing...uhm xbox yes. 360...

thsi deal repeats every other day, the price is too high, its $15 on ebay

If you're going to use bare SATA drives for backup, why not use a PCI SATA controller with one or two external ports (be sure to get one that supports hot swapping) - like the Rosewill RC-210 over on newegg? You'll still need external power. I've yet to see one of these controllers with a power pass-through and double-ended SATA power cord.
I've used SATA cardbus controllers on laptops - and, not using USB, the attached drives are actually perceptably faster than the internal one.