In less than 12 hours as I write this, the Deep Impact probe will slam into comet P/9 Tempel 1 (or just Tempel 1 to its friends). The impactor (an 800 pound mini-probe) has been released successfully, and is on its way to destiny. Impact is scheduled for 10:52 Pacific (US) time tonight.
If you live in the UK (or have access to the BBC), there is a program called StarDate that will cover much of the event live. I was interviewed for it the other day. My segment is with host Brian Cox, and we talk about the real-life science of the movie "Deep Impact". You can find more info on my bulletin board (with a picture too).
I'll be observing the comet tonight, using my school's new robotic telescope named GORT. If you want to see the impact for yourself, you'll need a fairly big 'scope (with at least an 8" mirror) and dark skies. If you want to know where to look, my old friend Jane Houston Jones has written an great article with many links to more info, including a finder image courtesy of Sky and Telescope magazine.
If you'd rather follow along on the web, try the National Optical Astronomical Observatory website. There are many, many professional 'scopes aimed Tempel 1's way, and they'll be updating their webpages in real time with images, and video. Here is a list of other web sources of live images.
Minute-by-minute mission updates are being posted at SpaceFlightNow.
Also, lots of people on the Bad Astronomy Bulletin Board are buzzing about this. Check out the General Astronomy forum for lots of discussions. I'll be posting there tonight from the observatory if I can.