In the blender game engine, are there any ways to cast shadows aside from using a sun lamp or a spot lamp?
If you are talking about just the "normal" lamp types (Point, Sun, Spot, Hemi, and Area), then no. The Sun Lamp and Spot Lamp are the only two that cast real shadows in the BGE. (FYI the sun lamp has only been able to cast shadows since 2.64).
You can use lighting tricks, like a fake shadow texture on a plane. Or transparent planes with the light cast pattern and beams.
You could even bake the lighting to textures and then use all shadeless materials in game.