Interleaving elements of two vectors?

[Ajay Narottam Shah]

Suppose one has

        x <- c(1,  2,  7,  9,  14)
        y <- c(71, 72, 77)

How would one write an R function which alternates between elements of
one vector and the next? In other words, one wants

        z <- c(x[1], y[1], x[2], y[2], x[3], y[3], x[4], y[4], x[5], y[5])

I couldn't think of a clever and general way to write this. I am aware
of gdata::interleave() but it deals with interleaving rows of a data
frame, not elems of vectors.

-- 
Ajay Shah                                      http://www.mayin.org/ajayshah  
ajayshah at mayin.org                             http://ajayshahblog.blogspot.com
<*(:-? - wizard who doesn't know the answer.