There is a Shuttle Launch currently scheduled 'No Earlier Than' September 28th, and the time has not been announced yet, for security reasons. It would be the Atlantis on STS 112.
An Atlas Rocket is also scheduled to be launched on Aug 21 at 6:09pm.
A night launch is very easy to see for at least 200 miles, daytime is less clear to see, but still very possible. If you are close to land or on land, you can listen to a rebroadcast of the shuttle audio with a standard scanner radio. If you're near Port Canaveral, it is on 421.750 (Cocoa Beach) and 146.940 (Merrit Island), and it's available on other frequencies in many other areas of the country.
The Launch Hazard Area (LHA) extends to 65 miles east of Cape Canaveral and they want all Mariners to be clear of the area about 2 1/2 hours before and 1 hour after any launch.
One thing that I only recently started to consider - if you were on the Wonder or the Magic and they had a Shuttle Launch, they have to recover those Solid Rocket Booster engines that fall back into the water. If the flight path had to be adjusted after they launched and those big things were falling back down to earth, I wouldn't want to be very close. Even with the fuel expended, they must still weigh a lot.