To recreate the historic endeavors to time transits from across the globe, you can partner with other individuals or groups worldwide and share your respective observations.  How do you find a match from a distant part of the earth?  Simply register for the global partner search.  Together you can then measure the sun's distance.

Using the free Transit of Venus Phone App, (available in iTunes version or in Android version) observers can time the transit from their location, submit the results to a collective pool of data, and calculate the distance from the sun to the earth, or the Astronomical Unit (A.U.). 

See the Links: Teacher Resources for lots of activities and educational information.