Hi, Jason. You can't boot the Powerbook in OS X to any USB device: this is a hardware limitation. So if the SSD is still connected via USB, that's one good reason why it isn't bootable. Assuming you instructed SuperDuper to make the clone bootable (I think that's a default setting in SD), it will have created a bootable software configuration on the SSD, so the only obstacle in your way now is the USB connection. In that case, the next step is to install the SSD inside the Powerbook, which I presume you intend to do anyway. Once it's installed, you'll be able to see whether it boots properly. I expect it will.
The Tibook only has slow USB 1.1 ports, and they're just not a practical way to connect any external storage device for regular use. Your very tedious one-time-only data transfer has already made you aware of this. So if you intend to use your 160GB drive for external storage and/or backing up the internal SSD, you'll want to buy a FireWire enclosure for it. A FireWire enclosure will enable you to boot to the external drive, and to read from and write to it faster than even USB2 would allow. Here's
one good inexpensive enclosure on Ebay for only $26 plus shipping. If you're not keen on buying from Ebay, here's another well-regarded enclosure:
http://eshop.macsales.com/item/Other%20World%20Computing/MOTGFW400/
EDIT: It now occurs to me that you said nothing about formating the SSD before you cloned to it. Did you use Disk Utility to format the SSD in Mac OS Extended format before cloning to it? If not, it's probably still in the Windoze format that was undoubtedly put on it at the factory, and it can't be used as an OS X startup disk in that format. If that's the situation, unfortunately you'll have to reformat it and then repeat the cloning process.
Message was edited by: eww