I'm a former seismologist with an abiding interest in all things scientific, especially the larger world around us. Here are pointers to cosmology and astronomy web sites, earthquake and general geophysics, history, art and more. In addition I enjoy weird stuff and the web provides ample opportunity to explore the strange side of humanity.
Astronomy I start every day with the Astronomy Picture of the Day. You'll find gorgeous pictures with brief, but informative, captions with ample hyperlinks; there is no more seductive site for general astronomy. Then there's the NASA news site; you can go there and subscribe to a daily newsletter.
Cosmology What is the answer to Life, the Universe, and Everything? Good stuff, such as discussion of the cosmological constant, entire universe simulations, and some great debates bearing on the cosmos.
Science, especially History Look in the science museum in Florence
and try to find Galileo's finger in a jar. Here's the history of mathematics.
A starting place for recent science news is Science
History of Art
Stock Market Terrific newsgroups at Silicon Investor, free to read, you have to pay to be able to post; the smartest high-tech investors go there (note: I wrote this around 1999; as of early 2003 it is uncertain that there are any smart high-tech investors). Technical analysis charting from Big Charts. Here's a pretty good tutorial on technical analysis.
Favorite Musicians Renaissance, a unique British band mostly from the 70s. Jane Siberry, so-called Canadian chanteuse (I don't know what that means), one of the most unusual of the singers discussed in the ectophile newsgroup and comparable to Kate Bush in my eyes. Speaking of whom, lets add Kate Bush to my favorite list.
Favorite TV Shows Doctor Who, Buffy: The Vampire Slayer, Stargate SG-1 and Babylon 5. These are just sample links. In general, when I'm researching important cultural trends I start my search at Webrings.
Favorite Search Engines Don't we all use Google? For hobbies and fan clubs (especially for TV and music), go first to Webrings and see what rabid enthusiasts with too much time on their hands have created.