The porkchop plot is nice, but it is not always an ideal presentation. I'm thinking of the case where I already have the mission in orbit. In this case, I don't care much whether days that pass are before or after the transfer burn; I just care about the ETA. In effect, if I move diagonally across the porkchop plot, I am looking at points of equal arrival time.

My first idea was to be able to use cursor keys such that left-right moves diagonally along lines of equal arrival time and up-down moves perpendicularly, increasing or decreasing arrival time.

However, for a given arrival time, I only am interested in the transfer which uses the minimum amount of delta-V.

Therefore I suggest presenting a graph whose X axis is arrival time and whose Y axis is minimum delta-V needed to arrive at that time. I believe the necessary information is already generated by the code which generates the porkchop plot.