Is there any value in getting an external hard drive with a grounded power supply? Would grounding the drive protect it from a static jolt from my hand when I pick it up? I've only really ever used the huge 5.25" external housings (they usually have an integrated power supply and use the standard heavy PSU cable with ground), and I need some more but noticed while shopping that the current trend is towards smaller enclosures with the external brick (and hardly ever grounded).
It would depend on if the ground was actually connected to the housing of the hard drive enclosure. There is a good chance that the housing is plastic, so grounding would be a moot point. It seems that several laptop brick power supplies plug into a 3-pin ground, but don't necessarily provide a ground line to the laptop itself. So unless you have knowledge of the pinouts from the power supply brick to the enclosure, it would be difficult to know if the case were actually grounded.
5.25" housing for a 3.5" drive?
Anyway, most of the recent housings I've touched have been plastic, so no chance of a shock at all.
The LaCie's I had were metal, but also grounded and, I'd hope, also insulated from the outer metal shell in any case.
You could always use an anti-static wrist-strap. Not that I've ever touched one, and I've not fried anything yet.