Betcha didn't know about this lil language feature
```
Python 2.6.7 (r267:88850, Oct 11 2012, 20:15:00) 
[GCC 4.2.1 Compatible Apple Clang 4.0 (tags/Apple/clang-418.0.60)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> ['%s %s' % (n, m) for n in [1,2,3] for m in [4,5,6]]
['1 4', '1 5', '1 6', '2 4', '2 5', '2 6', '3 4', '3 5', '3 6']
```