Duff,
To be perfectly honest, the answer is one word ....
INSURANCE
Stuffing bits of foam in-between keyboard and display, or using "trendy" wetsuit type contraptions, whether soft or rigid will not help. (e.g. useless against compression forces).
Just use a proper laptop bag or backpack. Brenthaven make some good ones, as do a few other maufacturers that I can't remember the name of....
Otherwise, just buy yourself one of those laptops that BT and the MoD like to use.... a Panasonic Toughbook. No need for any bag, they come with their own carrying handle !
Rugged Laptop Computers - Official Panasonic Toughbook Rugged Computers
While we're discussing protecting laptops in transit, which "off" offers the most protection to the HD when carrying a laptop about, hibernate, sleep or shut down completely or does it matter?
Are we talking traditional or solid state drives ?
For traditional drives, as long as the drive is not spinning then hibernate/sleep/shut down is a much of muchness because if you drop it hard enough you are still going to *** up the heads, which remember are less than a hair's width away from the platters.
For solid state I would guess it doesn't really matter which, and indeed is probably better techology than traditional drives for dropping.
But the best answer is .... prevention is better than cure !