If you lived on Jupiter you would be able to see a transit of Venus tomorrow. It might look something like the one we saw in June. Here is an example in SDO AIA 171, a time-lapse still of the black disk of Venus moving across the Sun. Even though the transit can't be seen from Earth, the Hubble Space Telescope may be able to see the small decrease in sunlight reflected off Jupiter toward Earth during the transit. SDO will help by telling the scientists how the Sun's brightness changes during the transit. Given how quiet the Sun has been of late, that should be pretty easy for us to do. Jupiter is ahead of the Earth in its orbit around the Sun, so the quiet side is rotating to face Jupiter, even as a new active region rotates into the view of the Earth.
First contact is at 0456 UTC, mid-transit is 0953 UTC and 4th contact is 1451 UTC (all September 20 UTC). That means the transit at Jupiter lasts almost 10 hours (compared to about 7.5 hours for the June 2012 Venus transit at Earth).
It's all part of our search for Earth-like planets around other stars. We see a lot of planets in the Kepler data; how can we determine which ones have water and oxygen?