These are some web pages and tools that I find useful. To appear on this list, the sites have to have changed my working life in some meaningful way.
Note, I have no affiliations to ANY of the links below - you click on them at your own risk.
General Computing tools
1) I often end up creating pdf files which are too big to e-mail. I use this website all the time and love it. It's a free online tool to turn a large pdf into a small one without losing any of the quality. They also have lots of other cool gadgets that I haven't tried. In the words of my colleague "this website changed my life". I think he was serious.
2) A beginners step by step guide to installing gfortran on Mac Yosemite. Many of the normal gcc compilers don't yet work on Yosemite, so this is an incredibly useful page for me.
http://www.lapk.org/gfortran/gfortran.php?OS=7 and the important Yosemite extra instructions http://www.lapk.org/gfortran/extranotes.php . If you can't remember the basics, this page shows you how to create and test a fortran helloworld.f90 program on a mac. http://laptops.eng.uci.edu/instructional-computing/incoming-students/getting-started-with-programming/fortran-tutorial I did find that I needed to save the program as fortran.f90, not fortran.f though. Finally, a make file intro here: http://genius2k.is-programmer.com/posts/40301.html
3) The people behind this website. They allow you to make and customise your own site with lots of beautiful templates, add your own domain name, host it and are hand 24/7 to answer any of your questions. Highly recommended
4) My favourite quick and easy image editor, Ribbet, now with a whole new look
1) Want to find out if it's raining right now over Africa? This product is used by national forecasters and provides rainfall images for the last 2 days.
2) The TAMSAT data page - want to see the up-to-date rainfall over Africa, click here.....
3) The beautiful and useful Weather Spark. Gorgeous graphics that show the current weather or climatology for most locations around the world. Check out their dashboard feature and their compare climates feature
4) The ever useful Weather Underground. Their awesome Wundermap is particularly good for extreme weather in the USA.
5) The lovely accuweather! Another forecasting staple and based in State College PA where I happen to live.
6) WeatherWorld. Loads of resources courtesy of Penn State Meteorology