SpaceRef Almanac
A broad source of space-flight information - daily updates, calendar of events, directory of space-related sites, discussion fora, and gateways to space science and astrobiology and the 'Whole Mars Catalog'. A service of Discovery.com.

StarDate
Plan your backyard stargazing with the celestial information gleaned from this web.

Leonardo Almanac
Collection of technology reference resources and statistics.

Handy Facts
A collection of handy facts about math, words, dimensions, space, and lots of useful and hard-to-find data.