Snopes checks out unbelievable tales, scams and urban legends and debunks (or confirms) them. Slightly less useful is the 100-strong webring of Unusual Museums of the Internet. These include the Virtual Toilet Paper Museum, the Old Calculators Web Museum and Signalfan's museum of traffic control signals. You can find links to lots of other offbeat sites via the Weird Site's Other Weird Links page. The Onion is the web's leading satire magazine, though with an American bias. Otherwise, for five minutes of fun, try browsing B3ta. This UK site sends out a weekly newsletter of cool links and runs a message board where people post amusingly manipulated pictures. But be warned: it's often offensive - that's part of the point - and most definitely rated NSFW (Not Safe For Work).
Another new category: being able to find stuff that's similar to music you like is increasingly important, both to listeners and to record companies trying to profit from niches. Last.fm requires an application that runs on your machine, and shows what other people with the same music like. Pandora says you need a US postcode; so give it one, then enjoy its expert-chosen stations. Liveplasma can search relationships in films as well as music. Tuneglue is a relatively new venture between last.fm and EMI, using data from Amazon and last.fm. Goombah requires a small download and only works on music in an iTunes library, but has been at it for some time.
Wikipedia now dominates the reference side of the web, partly because its pages are ranked so highly in Google. User-written, it's not always reliable, but is usually a good place to start. It competes with the Encyclopedia Britannica, which isn't free. However, another traditional alternative is the HighBeam Encyclopedia, which searches more than 57,000 articles from the Columbia Encyclopedia. Otherwise Jim Martindale's Reference Desk, started in 1994, provides an astonishing collection of links to reference sources. For words, try Onelook, which indexes more than 7.5m words in 931 dictionaries. It also has a reverse lookup to find words from their meanings. Finally, Teldir (on the infobel site) has links to the world's online phone books.
Alphagalileo gives a view of public-facing science in Europe and is a counterpart to eurekalert, the American Association for the Advancement of Science's press announcements forum. Space.com remains fascinating for all things spacey. Nasa contains a wealth of information. The growing importance of climate change makes the RealClimate blog written by climate change scientists important. realclimate.org