Avhaz: Lasse, my little brother.
Starlight: Megan Sanders, a fascinating person whose page I happened to stumble across.
Botany
Internet Directory for Botany: Botanical sites
Philosophia Botanica: Linné's book about botany in Latin.
Taxonomy
EUNIS – European Nature Information System: Information about the organisms of Europe.
Animal Diversity Web: Taxonomy of animals, pictures, sound files.
GRIN: Taxonomy of plants, tells e.g. the distribution of plants around the world.
Tree of Life: Taxonomy of all organisms, pictures.
Taxonomy Browser: Taxonomy of all organisms, quite thorough, has genetic information, you can search by scientific name.
Funet: Taxonomy of animals, plants and fungi.
Bioimages: A picture gallery of organisms arranged taxonomically.
Mammals of the world
Mark Isaak's list of peculiarities in scientific names.
Meanings of scientific species names of plants
Meanings of scientific names of dinosaurs
Meanings of scientific names of bacteria
MAGUS: Animal names in many languages.
Liber Herbarum: Plant names in many languages and medicinal use of plants.
Human being
Netanatomy: Human anatomy.
Genetics
Mouse genome
Palaeontology
Palaeos
Becoming Human: Palaeoanthropology, human evolution.
Dinosaurs
Russ Jacobson's site: this page has information of dinosaurs, gives also the meanings of scientific names.
DinoData: Scientific family names have English translations.
Dinosauricon
Dino Land
Pictures
Classic Nature Prints: Drawings of animals and plants.
Chemical Elements: Information about the elements.
Virtual Finland: Information about Finland.
CIA World Factbook
Atlapedia: Information about countries, maps.
Getty Thesaurus of Geographic Names: Information about the places of the world.
Coordinates of cities and distance of any two cities
Confluence: Site which is trying to get pictures of every longitude-latitude integer confluence on ground.
Maps of Finland
Perseus Atlas
Perry-Castañeda Library Map Collection: Maps from around the world.
MapQuest: Maps from around the world, also by coordinates.
World Atlas: Maps, flags and information about countries.
Map collection of the library of the University of Texas: Modern and historical maps from around the world.
Factmaps: Links to map sites.
Multimap: Zoomable map of the world. The bigger or more English speaking a place is, the more accurate map you'll get.
CGRER: Links to maps of USA, the world, countries and cities. Many of the links are obsolete.
Maps of Indo-European languages
Australia
Norway: You can choose between a map or a satellite image/aerial photo.
Terraserver: Satellite images of the world, resolution 15 m/pixel (better resolution if you pay the registration fee).
ESA: Click on ESA Multimedia Gallery, the page is searchable.
Math.com
OEIS: A database of integer series.
Pi
The Pi Pages: Information about pi.
The Pi-Search Page: You can search for any numbers from the first 100 million decimals.
Fractals
Fractal Gallery of Rio Club.
The Nine Planets: Information about the solar system.
ESA
U.S. Naval Observatory: Click on Data Services: Information about the location of sun, earth and moon, the phases of the moon, eclipses, etc.
Earth and Moon Viewer: Shows what the earth and the moon look like from different directions and with different imaging methods.
NASA's image archive.
Space telescope Hubble and its images
Heavens-Above: Orbits and fly-by times of satellites, shuttles the international space station.
NASA: A java program which shows the orbits of asteroids and comets.
Eridos Astronomia: Pronunciation and etymology of the names of astronomical objects.
Clouds
Weather around the world
Public Library of Science: Scientific articles.
Extreme Science
NOVA
Factmonster: Information about different branches of science. Index.
How Stuff Works: Tells how machines, technology, biology, natural phenomena, economics, and everything works.
JavaScript
Juicy Studio: JavaScript tutorial
TheFreeDictionary: Dictionary, thesaurus and encyclopaedia.
Wikipedia: An encyclopaedia which everyone can modify.
Hyperhistory: A great site which has timelines and maps about history, religion, science, arts, etc.
World History Project: Information about world history from Mesopotamia until World War II.
Din Timelines: Timelines about world history.
On This Day: Tells what happened and who was born or who died on any day of the year.
Factmonster: Same kind of page as On This Day.
American Memory: Database of the culture and history of USA.
Ellis Island: You can search for immigrants who moved to USA.
Encyclopaedia Romana
VRoma
Forum Romanum
Reconstruction images of Rome
Ancient History: History and mythology of Rome and Greece.
Roman gods
General information
Beliefnet
Academic Info
Religious Tolerance
Christianity
Catholic Encyclopedia: An encyclopaedia of the Catholic Church about Christianity.
Encyclopedia Mythica: Whole world.
Wikipedia's page of mythology.
A Europe of Tales: Myths of Europe. The site is made with Flash, so it's a bit slow.
Ancient History: History and mythology of Rome and Greece.
Roman gods
Valhalla Warriors: Scandinavia.
Wikipedia's page about mythological creatures.
Demons and spirits
Kittens
Sidewalkchalkguy: 3D drawings on streets.
Minagi: See also this.
Tessellation
Mosaics of New York made of photos
Clipart
Pages of medieval books
Lyrics
LyricsFreak
LetsSingIt: Click ARCHIVE on the menu in the top of the page.
Leonard's World
EarthCam
Globocam
The Media Channel
Webcams in Great Britain
Dancing Bush
Dumb Laws from around the world. Check also out the other sites under the header The Dumb Network.
BBC
The Los Angeles Times
The Sydney Morning Herald
List of cosmetics.
Royalty: Information about monarchies and royalties of the world.
Thinkquest competition partakers. Thinkquest is about making a web site of an educational subject.
Rhetorical terms: Shorter => easier to use.
Rhetorical terms: Longer => more thorough.
Web site lists of many countries
FBI: Most wanted criminals.
Maya calendar
Mixed Signals: Synesthesia.
The coats of arms of Finnish municipalitites