Despite the advances in computing technology, neither PowerPoint nor TTVS (Tactical Terrain Visualization System) has the impact of physically walking through the terrain as you give the mission briefing. A good walk-through sand table, in conjunction with TTVS, provides excellent visualization of the battlefield. Plus, it also makes for great, albeit juvenile amusement.
"You wanna see eighty captains move really fast? Tell them they're going home [after they pick up all these paper bowls]".