I rented the Canon 800mm f/5.6 IS, bought a sheet of solar film, and flew to San Francisco to view and photograph the 2012 transit of Venus! It was a huge financial risk, but paid off completely, the weather was perfect, the viewing was spectacular, sunset was just superb.
Did a little star and moongazing too, as the night before was a partial lunar eclipse. Everything about it was excellent and it has made for some pretty decent shots, too! Enjoy.