Would it be possible to add a module that calculates a sub-orbital hop? Like the the landing AP with the ability to select from the map/type coordinates and then have MJ calculate the required burn and heading to launch you from your current landed coords to the the ones selected?

This could be first calculated as a two burn impulsive Lambert transfer, taking into account the coriolis velocity of the celestial body. A complication would be if the optimum transfer went through the surface or terrain, so there would need to be path constraints. A much, much further complication would be aerodynamics, but I don't think most players want this feature for Earth/Kerbin but for Moon/Mun/Minmus/etc (EDIT: looks like someone wants this for F9-grasshoppers in #1004).

That impulsive trajectory would then need to get further refined by finite burn algorithms.

Leaving this one open since its likely to be some kind of v2.0 of the #1052 rewrite.