In Firefox and some other tabbed interfaces, I can use Ctrl-PgUp/Down to cycle through tabs sequentially, based on their order in the tab list. I associate what is what based almost entirely on its position along the tab bar and what is next to what, so this is extremely useful for the way I keep track of things in my head.
However, I haven't been able to find an equivalent for actual taskbar items in Windows, such that with a single shortcut will switch focus to the task item either to the left or the right of the current task in focus. There's a lot of existing shortcuts that I use (Alt-Tab, Ctrl-Esc, and their counterparts), but these use the window manager's stacking order, so it always changes based on what you've switched between in the past, and so their usefulness generally only lies in switching between two apps -- above that, I just can't keep that kind of stack in my head.
The closest shortcut I've found is Winlogo-Tab, but it only moves a selector on the taskbar, so you have to hit space after moving it, and it also seems to originate the selector from the leftmost item every time (rather than relative to the current item).
Am I just a weirdo and will have to write my own app to perform these actions?