I would like to have the time line and key frames be in seconds instead of frames. When I animate something at 30 fps and then decided to change it to 60 fps the animation will play at twice the speed.
Press Ctrl + T with your mouse inside the timeline. This toggles that view. Do that and the timeline will depict parts in frames instead of seconds. This is useful for if you want it to be in seconds.
It can also be accessed via the view menu.
Of course, there are times when one is preferable over the other.