Python 2.6, 347 chars
import re
W,x={},"a and i in is it of or the to".split()
[W.__setitem__(w,W.get(w,0)-1)for w in re.findall("[a-z]+",file("11.txt").read().lower())if w not in x]
W=sorted(W.items(),key=lambda p:p[1])[:22]
bm=(76.-len(W[0][0]))/W[0][1]
U=lambda n:"_"*int(n*bm)
print "".join(("%s\n|%s| %s "%((""if i else" "+U(n)),U(n),w))for i,(w,n)in enumerate(W))
Output:
_________________________________________________________________________
|_________________________________________________________________________| she
|_______________________________________________________________| you
|____________________________________________________________| said
|_____________________________________________________| alice
|_______________________________________________| was
|___________________________________________| that
|____________________________________| as
|________________________________| her
|_____________________________| with
|_____________________________| at
|____________________________| s
|____________________________| t
|__________________________| on
|__________________________| all
|_______________________| this
|_______________________| for
|_______________________| had
|_______________________| but
|______________________| be
|_____________________| not
|____________________| they
|____________________| so
