Check Twitter for available usernames

twitter.txt

test1
test2
...

twitterchecker.py

from time import sleep
from urllib2 import urlopen


for l in open('twitter.txt', 'r'):
    l = l.strip()
    if not l:
        break
    try:
        urlopen('http://twitter.com/%s' % l.lower()).read()
        print '%20s is NOT available!' % l
    except:
        print '%20s is available!' % l
    sleep(0.5)