Three.js exporter for new version of Blender 2.60 supports many features. The problem is that default exporter settings generates quite big JSON file even for small models.

Here is list of defaut options for save model function from export_threejs.js:

         filepath = "",
         option_flip_yz = True,
         option_vertices = True,
         option_vertices_truncate = False,
         option_faces = True,
         option_normals = True,
         option_uv_coords = True,
         option_materials = True,
         option_colors = True,
         align_model = 0,
         option_export_scene = False,
         option_lights = False,
         option_cameras = False,
         option_scale = 1.0,
         option_embed_meshes = True,
         option_url_base_html = False,
         option_copy_textures = False,
         option_animation = False,
         option_frame_step = 1,
         option_all_meshes = True

These are good settings when you want to save all objects from scene. It is quite overkill when you need to save just one dynamically generated object. I recommend to turn off following options:

option_all_meshes, option_materials

Here is sample code in Python which will select object by name and save it to file with defined options:

import bpy

bpy.ops.object.select_name(name="ObjectName")
bpy.ops.export.threejs(filepath="ObjectName.js", option_all_meshes=False, option_materials=False)

Further articles about Blender and Python are located under the tag Blender on my blog.

Enjoy :)