There are only a handful of launches left before the space shuttles retire in 2010.  I highly recommend everyone see one of these things go up.  It's just an amazing experience for young and old alike.  I've seen 17 shuttle launches and probably close to 100 unmanned rocket launches and it still doesn't get old.  If you're close enough, the roar of the launch can set off car alarms.  I've linked to a map from the local newspaper that gives you prime spots to view a shuttle launch for free.  I also recommend making flexible travel plans because these things are often delayed.  And if a launch is pushed back, there's always Disney, the beach, or a million other touristy things.