I think a useful utility function is to chose a random element from an array. Python has this in random.choice. Here is what a Julia implementation might look like:

function choice(a::Array)
    n = length(a)
    idx = mod(rand(Uint),n)+1
    return a[idx]
end

An option would be to have an additional argument for drawing some number of samples. This would be sampling with replacement from an array with uniform probability.

Another useful function could be to have sampling without replacement.