It does have AC power and it is USB.
It is a SATA enclosure. This is the one I bought from newegg:
http://www.newegg.com/Product/Product.aspx?Item=N82E16817106099
ok - pull the ac adaptor out of the enclosure and plug the usb lead it into one of the usb ports on the MacBook (no hubs !)
What happens now ?
The unit turns on, I can hear and feel the drive moving, but no mounting.