TaskArrange is a simple utility that lets you rearrange the buttons of the Windows taskbar.

Sometimes we open our programs in a specific sequence, to keep their taskbar buttons in a desired order. But what happens if a program crashes or we close it, and then we open it again? That's right - its task button ends up last in the taskbar. Windows itself does not allow us to move the task buttons around, so we are stuck with two options: either accept the new order, or close everything and reopen them in the preferred order. TaskArrange brings an end to this annoyance, by letting us do exactly what we want: reorder the task buttons.

(Ok, it's not a productivity tool per se, but it can help you be more productive)