ticks outside the axes?

Is there anyway to place the tick marks so that they are located outside the axes, i.e. on the same side of the axis line as the axis labels?

With plots such as imshow and pcolor and even some busy line plots, the interior minor ticks are completely obscured and the exact location of the major ticks is ambiguous.

It would be nice to be able to specify the ticks as inside or outside (or both), right or left (or both), top or bottom (or both). This functionality may already be present but I cannot figure out how to invoke it if it is.