Agreed with Bernie - though I doubt it would be scratching the platters - the heads are designed to move across them at incredible rates, so I doubt it moving across them with it turned off will do any further damage. As for the shaking... hmm - I certainly wouldn't have done that if there's critical data to come off them.
There's no harm in trying it in your new PC - it can't damage anything, only not work.
As for methods of recovery - in theory you can replace the board if you can find the same exact model somewhere (Ebay would be your best bet). This would be the cheapest way, but it's not something I would do myself (I suck at that sort of thing).
My own personal choice would be to get a USB IcyBox (either for SATA or IDE, whichever it is), and try that. I've had a lot of luck with broken drives working when they're given their own dedicated power - I've got 3 broken disks now (one a laptop drive) that still work if powered externally, yet aren't recognised if connected to the internal PSU. It's around £20 for an IcyBox (at Scan.co.uk), and if it does work, it'll be by far the cheapest way. Even if the drive doesn't allow access in My Computer, try to use something like Acronis True Image to create an image, and then mount that image as a virtual drive, using that instead of the broken disk.
After that you're down to specialist recovery companies. I've never used one myself, and as such can't recommend one, but you're probably looking at something between £400 and £600, though there's a few variables involved such as the condition of the drive, how much data there is, etc.
My finger is pointed firmly at the PSU for multiple drive failures. Any cheap one will eventually cause this sort of problem, and it's not unknown for a faulty one from a reputable manufacturer too. The only other thing that could really do it is overclocking while not limiting the PCI or PCIe bus - SATA drives can fail that way - or poor quality feed of electricity into the room/house. In that final case, the only thing to do to fix it is to get an Uninterruptable Power Supply.
Edited 1 time(s). Last edit at 01/16/2007 09:57AM by gav.