WiFi at ATL?

Last Thursday, when my wife and I arrived at Hartsfield Jackson Atlanta International Airport (ATL), I tried getting WiFi, but found that it wasn't free. Once again, several days ago on Monday evening, I tried once again, but to no avail before boarding our plane.
However, apparently there is a way at ATL to get the WiFi for free (HT: lifehacker):

I found that I could easily visit sites like slashdot, google, or even this weblog, when adding a ?.jpg at the end of the url.

Pretty neat, though I'm not sure when the next time I will be in Atlanta.