New
#41
Here's one thought, a silicon case to use with a cable like Steve linked to.
StarTech HDDSLEV25 HDD Accessory - Newegg.com
EDIT: The link Steve has for the Amazon protective cover is better.
I have two of these external enclosures, they are light weight and pocket-sized.
Amazon.com: Kingwin 2.5-Inch USB 2.0 External Hard Drive Enclosure - Aluminium, ATK-25U-BK (Black): Computers & Accessories