How can I convert a dictionary into a list of tuples?

If I have a dictionary like:

{'a': 1, 'b': 2, 'c': 3}

How can I convert it to this?

[('a', 1), ('b', 2), ('c', 3)]

And how can I convert it to this?

[(1, 'a'), (2, 'b'), (3, 'c')]