Blender 2.68a Python 3

I want to set texture for faces. I put (and googled) together a quick example using the "Cube", and having an existing BMP as texture file on disk. I am object-mode. I set the Viewport Shading to texture.

The code is:

import bpy
import bmesh

texturak = bpy.data.textures
o = bpy.data.objects["Cube"]
me = o.data
ol = me.materials

img = bpy.data.images.load('d:\\canwall1.bmp')
texturak.new('ColorTex', type = 'IMAGE')
texturak[-1].image = img

mat = bpy.data.materials.new('TexMat')
mtex = mat.texture_slots.add()
mtex.texture = texturak[-1]
mtex.texture_coords = 'UV'
mtex.use_map_color_diffuse = True 
mtex.use_map_color_emission = True 
mtex.emission_color_factor = 0.5
mtex.use_map_density = True 
mtex.mapping = 'FLAT' 

if (len(me.uv_textures) == 0):
    me.uv_textures.new()
while (ol):
    ol.pop(0,update_data = True)
ol.append(mat)

for texlay in me.uv_textures:
    for tf in texlay.data:
        tf.image = img
    

I get the cube, then the texture, I addit as a material. Nahh well from there I found no good examples on internet. Only working stuff was 2.5 and some guesses from the answer of my previous question here.

So for this time I tried to set all face-image to the image I load. But all I get is a purple cube. Now my guess is that "something happened" (woohoo), but as well as "somthing is missing" (no woohoo this time).

My question would be to those more experienced, that what is missed here actually, or is there a better way to set material / texture to a face / faces?

Edit: To extend my question: I want to have more textures per mesh, this is why I want to set the texture per face.