http://www.skypub.com/ - Sky and Telescope astronomy webpages
http://xaos.theory.org/
- XaoS, realtime fractal zooming program
http://www.nicefire.fsnet.co.uk/ - Nice fire indeed! Balloons and cynical gubbins from someone else who shares an unhealthy fascination with all things that burn very quickly.
http://www.101science.com/RFSim99.exe "RFSim99 is a linear frequency domain circuit simulator geared towards quick and easy simulation of radio frequency circuits." That's what it says. 2Mb download and very handy indeed.
http://eznec.com/index.shtml EZNEC antenna simulator. Evaluation version only allows 20 segments, but this is sufficient to simulate simple wire antennas.
http://spanky.triumf.ca/www/fractint/fractint.html
- Fractint webpage. Get it right now.
http://www.david-taylor.pwp.blueyonder.co.uk/software/wxtrack.htm WxTrack is a good satellite orbit predictor. Easy to use, and geared towards weather satellites.
http://www.mt.net/~watcher/new.html I'm not sure what this is, but it's quite funny. A whole range of fascinating links to utter nonsense.
If you are ever bored, then a few phrases for the search engines guaranteed to provide a laugh are:
"Fake moonlanding"
"Atlantis"
"Conspiracy theory"
"Aliens"
"Ufos"