|The stupid question is the question not asked|
They don't appear to do anything in any of the apps I use.
Exactly. This leaves it free as a modifier for custom mapping. Under Windows, there are some defaults (Win-L locks the display, Win-D shows the desktop, etc.), and there are third-party apps that let you map it to do more. I use one called WinKey (which isn't made anymore, sadly). When I want my browser up, Win-W. Win-P begins an Eclipse/EPIC session with a blank .pl file. And so on.
In Linux and BSD, they key is assignable to window-manager tasks (as the modifier 'Hyper' in most cases). On my linux devel box, Win-D starts my development environment (Eclipse/EPIC, Devel::ptkdb, and a couple other tools).
On the Mac, it's basically the PC world's "control" key, so almost all apps use it.
But, on any PC-based platform (damn it, I can't say 'x86-based' anymore!), it's one of the most useful keys because you can make it do whatever you want.
ScrollLock, though... what a pointless key. (Keyboard holy war! Yay!)
A collection of thoughts and links from the minds of geeks
The Code that can be seen is not the true Code
"In any sufficiently large group of people, most are idiots" - Kaa's Law