Word fractal plotter
Python (518)

from pylab import*
D=dict(zip('ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789',[map(int,bin(7145037215283832782017591362181079009730769141301710950254702714880607436795)[2+n*7:9+n*7])for n in range(36)]))
def T(A,C):y,x=A.shape;M=zeros((2*x-1,x+y));p=A[::-1].T;q=A.T[::-1];M[:y,:x]=C[0]*A;M[:x,:y]=C[1]*p;M[:x,-2*y:-y]=C[2]*q;M[x-1:x-1+y,:x]=C[3]*A;M[x-1:,:y]=C[4]*p;M[x-1:,-2*y:-y]=C[5]*q;M[2*x-1-y:2*x-1,:x]=C[6]*A;return M
def R(S,N):
 V=ones((1,3))
 for i in range(N):V=concatenate([T(V,D[C])for C in S],1)
 ion();imshow(V)

Call as R('CODEGOLF', 3)
first i make a dictionary that maps letters to their 7-bit SSD-representaion, where each bit stands for one bar, the .-corners are simply overwritten by the most recent bar
.000.
1   2
1   2
1   2
.333.
4   5
4   5
4   5
.666.

The function T(BaseArray, BooleanArray) makes a big empty array for one letter and puts rotated copies of BaseArray along the bars as indicated by BooleanArray. Finally R(String, N_levels) connects all the letters form the input and uses the result as BaseArray for the next iteration.
While technically correct, the result is quite ugly because of interpolation and the default colourmap

Unglofed
from pylab import*
D=dict(zip('ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789',
           [map(int,bin(7145037215283832782017591362181079009730769141301710950254702714880607436795)[2+n*7:9+n*7])for n in range(36)]))

def T(A,C):
    y,x = A.shape
    M = zeros((2*x-1,x+y))
    if C[0]: M[:y,           :x] = A
    if C[1]: M[:x,           :y] = A[::-1].T
    if C[2]: M[:x,      -2*y:-y] = A.T[::-1]
    if C[3]: M[x-y+y/2:x+y/2,:x] = A # middle bar shifted upwards by half thickness
    if C[4]: M[x-1:,         :y] = A[::-1].T
    if C[5]: M[x-1:,    -2*y:-y] = A.T[::-1]
    if C[6]: M[2*x-1-y:2*x-1,:x] = A
    return M

def R(S,N):
    V = ones((1,3))
    for i in range(N):
        V = concatenate([T(V, D[C]) for C in S], 1)
    imsave('%s_%s.png'%(S,N), V ,cmap='gray')

The initial seed V kinda controls the font on the deepest level. [1 1 1] make the smallest possible 3x5 letters

With V = ones((1,11)) you get long and thin letters

And with
V=array([[0,1,1,1,1,1,1,1,1,0],
         [1,0,0,0,0,0,0,0,0,1],
         [0,1,1,1,1,1,1,1,1,0]])

you can make hollow letters