Faster way to do this?

[Skip Montanaro]

    Freddie> I'm not sure what it's called. You're given a set of letters
    Freddie> ('olhel', for example), and you're supposed to come up with a
    Freddie> bunch of words that use only those letters. In this case, it
    Freddie> might be ('he', 'hell', 'hello', 'hoe', 'hole', 'oh'). 

Boggle?

My version is appended to this note.  Here's the output on my machine for
your version and mine:

    % python findwords-orig.py hello
    Read 234937 words in 1.12s
    Method 1: found 17 words in 6.39s
    % python findwords.py hello
    loaded 234937 words into dictionary in 1.11 seconds
    found 17 words in 0.00 seconds

Skip

import sys
import time

WORD_FILE = "/usr/share/dict/words"

start = time.time()

dictionary = {}
wf = open(WORD_FILE, 'r')
for line in wf:
    dictionary[line.strip()] = True
print "loaded %d words into dictionary in %.2f seconds" % (len(dictionary),
                                                           time.time()-start)

def findwords(dictionary, letters, prefix="", seen={}):
    for i in range(len(letters)):
        newprefix = prefix+letters[i]
        if newprefix in dictionary and newprefix not in seen:
            print newprefix
            seen[newprefix] = True
        findwords(dictionary, letters[0:i]+letters[i+1:], newprefix, seen)

if __name__ == "__main__":
    start = time.time()
    findwords(dictionary, sys.argv[1].lower())
    print "found matches in %.2f seconds" % (time.time()-start)