Picasa Photo Organizer :: After Google's takeover of Picasa, they have released the latest version of their photo organizer for free. I've played around with it a bit, and I'll have to say it is one of the best programs of its kind out there. There are a few caveats, but give it a test drive if you have the chance, especially if you know that you have a lot of digital images on your computer but you've lost track of where they all are.
Robotics
Mars Rovers Homepage :: All the details about the latest trekkings of the NASA rovers on Mars.
Photius.net :: Justinm's senior design project website, complete with pictures and movies of the award-winning autonomous cat Photius.
UTDallas AUV Team :: The Autonomous Underwater Vehicles Team at the University of Texas at Dallas competes annually in the AUVSI International Autonomous Underwater Vehicles Competition.
Science
SpaceWeather.com :: All the latest info about things going on outside of the bubble we call Earth. News about the sun, planets, and all other things extra-terrestrial.
Technology
Engadget :: Engadget is one of the best technology website for tracking product announcements, rumors, and releases.
Slashdot :: If you don't know what slashdot is, you probably don't care.
Weather
College of DuPage Main Radar Page :: One of the best resources out there for free, up-to-date Nexrad radar data, including full reflctivity and velocity scans for select sites during severe activity.
Flickr :: Flickr is an online repository for all of your images. My flickr stream is what generates the images at the top of the main page, using rss and the magpie php rss parser.
Google Maps :: Hands down the best web-based mapping site out there.
Google Suggest Beta :: In the latest from everyone's favorite search engine, Google give you results as you type.
Weblog
Textpattern :: The software that runs this site. So much for security through obscurity.
Wordpress :: Another good weblogging program. For PHP hacks, this one is probably the most extensable. Unfortunately, I found the way that it organized and displayed information to be crude and difficult to deal with.