Python: merge lists

A simple utility function to merge several lists in a single one, using the functional programming tools:

def merge(*input):
    return reduce(list.__add__, input, list())

Example:

>>> a = [0, 1, 2]
>>> b = [2, 3, 4]
>>> c = [4, 5, 6]
>>> merge(a, b, c)
[0, 1, 2, 2, 3, 4, 4, 5, 6]

The same but removing duplicates:

def merge_uniq(*input):
    return list(reduce(set.union, input, set()))

The same but removing duplicates later:

def merge_uniq(*input):
    return list(set(merge(input)))

Other (easier) ways to achieve the same?

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