Is it possible to align Windows 7 taskbar buttons?
Solution 1:
It's actually possible with 7+ Taskbar Tweaker.
More details here.
Solution 2:
Answering my own question.
It is sort of possible.
If you set Taskbar Properties → Taskbar Buttons: "Always Combine, hide labels" you will get narrow taskbar buttons (approximately 52 pixels wide) that will always align with the one above it consistently.
Unfortunately the MinWidth Taskbar registry tweak doesn't work with this setting, so I can't make the buttons wider.
I'll leave this question up and hopefully the author of 7+ Taskbar Tweaker will see it and say, "Hey! That's easy! I'll include an option for this in my next release!" Hey, I'm an optimist. ;)