STS-116 is scheduled for launch at 9:35 Eastern time on Thursday (for those of you who don't read blog post titles). This is a mission to the space station (they all will be except for the one to Hubble in 2008). The weather may scrub the launch for now, with only a 40% chance of launch.
Still, if it goes off, it'll be a night launch, which is cool. The one Shuttle launch I have seen -- which lifted a camera I worked on for Hubble -- was at 3:00 a.m. and it was spectacular. BABloggee Daniel Crawford let me know that this launch tonight (if it launches on time) should be viewable all up and down the east coast of the US. He also told me this launch is similar to one that happened in September 1997 when the Shuttle met up with the Mir space station. Back then, some timings were posted to a satellite observers group. The launch trajectory for this mission does look pretty similar, so I'm thinking the timings should be pretty close.
If you want to see the Shuttle on its way up, check that page and make sure you get out a few minutes before the time it says, just to make sure -- in other words, immediately after launch. The page gives the time in minutes after launch you can see it at its highest from your location, that height above the horizon in degrees, and the azimuth (0 = north, 90 = east, 180 = south, 270 = west). For most of those locations, the Shuttle will be pretty low to the horizon, and towards the southeast. Make sure you have a clear horizon in that direction or you'll miss it.
Again, the mission has a pretty big chance of being scrubbed, so keep your ears open for the news.