Future flares could dwarf these. NanoSail-D is skimming the top of Earth's atmosphere and slowly descending as it circles the planet. As the spacecraft gets closer to Earth and aerodynamic forces flatten the fabric into an ever-better reflector, flares are likely to intensify, theoretically exceeding the brightness of Venus as much as 100-fold (5 magnitudes). Photograph one of those and you just might win $500.
http://www.spaceweather.com/