How does your favorite starship measure up against all others in science fiction? You need wonder no longer, thanks to Jeff Russell's Starship Dimensions, a site that obsessively measures the lengths of every spaceship ever and puts them all together in a handy chart. It turns out the Death Star from Star Wars is bigger than Rama from Rendezvous with Rama, and Macross Super Dimensional Fortress One from Macross is like twice as big as the U.S.S. Enterprise. Russell consults original blueprints and special-effects creators to obtain exact lengths. [Jeff Russell's Starship Dimensions]
By the way, if anyone finds themselves at the Museum of Science Fiction in Seattle, nestled under the phenomenally pointless EMP musuem (and I'm a big music fan), they have a really cool digital "window" looking out on a starport where you can bring up many of the most notable ships from Science fiction. It's cool.