hrmm, I bought the National Geographic Topo! software and it can do that much. Seems like a good idea until you try it - very cumbersome. I'm hoping for something more like getting directions from mapquest - enter the to/from locations and it does all the drawing for me.
I may need to buy DirectRoute for that, I guess. Like I said before though, this feature isn't a priority, it'd just be really nice to have.