They're not docked. The space shuttle will dock with the ISS on Day 2 of the shuttle mission, in the meantime, STS-121 is in "catch up" mode with the ISS.
oops I read here on FreeRepublic earlier that they were docked. Go here and find out when you can see it from your place. http://www.heavens-above.com/. If tht was just the ISS it was still more impressive than a no dong :-)
Its going to be back on 6 July at 10:51 PM on the west coast. Do you think they'll be docked by then?