Combining two Series into a DataFrame in pandas

I have two Series s1 and s2 with the same (non-consecutive) indices. How do I combine s1 and s2 to being two columns in a DataFrame and keep one of the indices as a third column?

I think concat is a nice way to do this. If they are present it uses the name attributes of the Series as the columns (otherwise it simply numbers them):

    In [1]: s1 = pd.Series([1, 2], index=['A', 'B'], name='s1')

    In [2]: s2 = pd.Series([3, 4], index=['A', 'B'], name='s2')

    In [3]: pd.concat([s1, s2], axis=1)
       s1  s2
    A   1   3
    B   2   4

    In [4]: pd.concat([s1, s2], axis=1).reset_index()
      index  s1  s2
    0     A   1   3
    1     B   2   4

Note: This extends to more than 2 Series.