Starting at 9PM on 23 January 2015, a series of moon and shadow transits occur on the face of Jupiter. This page is setup to assist in observing these varied events.
Here is some background:
http://www.skyandtelescope.com/observing/dont-miss-jupiters-shadow-trifecta/
Video from NASA:
https://www.youtube.com/watch?v=YWlYTppifhI&feature=youtube_gdata
If you are clouded out or can't get out to observe the events, there is this link to a real time video cast from Griffith observatory (it has a nice simulation):
http://new.livestream.com/GriffithObservatoryTV/JupiterTripleMoonShadowTransit
You should be able to click on an image to see a larger version