The human genome
is about 3,120,000,000 base pairs long, so half of that is in each spermatozoa
-- 1,560,000,000 base pairs
Each side of these base pairs can either be an adenine-thymine or a guanine-cytosine bond, and they can be aligned either direction, so there are four choices. Four possibilities for a value means it can be fully represented with two bits; 00 = guanine, 01 = cytosine, and so forth.
The figures that I've read state the number of sperm in a human ejaculation to be anywhere from 50 to 500 million. I'm going to go with the number 200,000,000 sperm cells, but if anyone knows differently, please tell me.
Putting these together, the average amount of information per ejaculation is 1.560*109 * 2 bits * 2.00*108, which comes out to be 6.24*1017 bits. That's about 78,000 terabytes of data! As a basis of comparison, were the entire text content of the Library of Congress to be scanned and stored, it would only take up about 20 terabytes. If you figure that a male orgasm lasts five seconds, you get a transmission rate of 15,600 tb/s. In comparison, an OC-96 line (like the ones that make up much of the backbone of the internet) can move .005 tb/s. Cable modems generally transmit somewhere around 1/5000th of that.
If you consider signal to noise, though, the figures come out much differently. If only the single sperm cell that fertilizes the egg counts as signal, you get (1.560*109 * 2 bits) / 5 s = 6.24*108 bits/s, or somewhere in the neighborhood of 78 Mb/s. Still a great deal more bandwidth than your average cable modem, but not nearly the 5,000,000 Mb/s of the OC-96.
See also: the E2 Sperm Counter.