If you need a reminder that Bob Dylan is one of the coolest guys on the planet, check out the new video for "Thunder on the Mountain," from his excellent 2006 album, Modern Times. Not only is this a great song, but the video is also a great trip, chronicling the many guises of the formerly nostalgia-phobic Bob over the years. Using archival concert footage and other documentary-style shots, the video traces the history of Dylan from his early Don't Look Back days through the 1970s and '80s and into these, er, modern times.

Better yet, Slate, which premiered the video on Friday, has come up with an awesome contest for die-hard Dylan fans using 20 images from the "Thunder on the Mountain" video. Readers who can identify the year in which each of the 20 images were filmed can enter to win a guitar signed by Bob himself.