This is SOOOOO cool!  From SpaceWeather.com:

Last week, Comet 17P/Holmes shocked sky watchers around the world with a sudden million-fold increase in brightness. It literally exploded into view, rapidly becoming a naked eye “star” in the constellation Perseus. Since then the comet has expanded dramatically. It is now physically larger than the planet Jupiter and subtends an angle in the night sky similar to the Moon’s Sea of Tranquility, the right eye of the “Man in the Moon.” Photographers, this amazing comet is an excellent target for off-the-shelf digital cameras and backyard telescopes. It grows visibly from night to night and no one knows how large it will become. Stay tuned to http://spaceweather.com for sky maps and the latest images.