Another (admittedly trivial) experiment with speed and storage: Iterating through a 10,000 element list was about 2% slower than iterating through a 10,000 element tuple, and the list was 16 bytes bigger than the tuple:

  #!/usr/bin/python

  from sys import getsizeof
  from random import sample
  from time import time

  l = sample(xrange(10000), 10000)
  t = tuple(l)

  print "The tuple's size is " + str(getsizeof(t)) + " and the list's size is " + str(getsizeof(l))

  s = time()
  z = 0
  for x in l:
    z += x

  print "Iterating through a 10,000 element list took " + str(time() - s) + " seconds."

  s = time()
  z = 0
  for x in t:
    z += x

  print "Iterating through a 10,000 element tuple took " + str(time() - s) + " seconds."


  doug@supermicro:~$ ./x
  The tuple's size is 80056 and the list's size is 80072 
  Iterating through a 10,000 element list took 0.00589299201965 seconds.
  Iterating through a 10,000 element tuple took 0.00538778305054 seconds.

  doug@supermicro:~$ ./x
  The tuple's size is 80056 and the list's size is 80072
  Iterating through a 10,000 element list took 0.00553607940674 seconds.
  Iterating through a 10,000 element tuple took 0.00536203384399 seconds.