So I'm trying to learn about valves as research for my column in Engadget next Saturday, and I stumbled across The Virtual Valve Museum, which has loads of pictures of wierd valves, including this Mercury Arc Rectifier. Just imagine finding that hiding out in the back of your guitar amp! Also, if you've just formed a band and are looking for a name, visit the site. It has sections on Heil Tubes, Micropups, Strobotrons, Surge Arrestors, Thyratrons, Trigger Tubes, Glow Modulators, Heptodes, Nuvistors, and, of course, Klystrons.