As TomPalm points out, with a Garmin, once you have chosen a destination, you can add a place as a stopping point between where you are and your destination. I don't know if there is a limit as to how many via points you can add.
Also, with some of the newer Garmins you can program in different routes (as opposed to different destinations) that you want to save. Thus, you could program from A to B and B to C and C to D.
Finally, a few Garmins will allow you to say that you are interested in going to a set of destinations (A, B, C, D, and E) and then it will choose the fastest way to get to all of them. If B, C, and D are all in between A and E, I presume it will take you there in that order.