Twisted Sifter A collection of my favourite postings on Twisted Sifter.
Steampunker.ru A collection of my favourite postings on Steampunker.ru (Russian).
EasyEDA An excellent browser-based electronic design tool, featuring schematic design, SPICE simulation, and PCB layout. They even provide a PCB manufacture servce which you can use directly from within the software.
PCBWeb A free CAD application for designing and manufacturing electronics hardware.
PartSim A excellent free online schematic editor and circuit simulator - I've used it often for sharing circuits with people. I like the ability to save waveforms and simulation results as PDFs - makes presentation easy!
The JOSS Research Institute (http://jossresearch.org/) Run by Jon Singer (http://www.jonsinger.org/), he carries out research on dye lasers, nitrogen lasers, ceramics, glazes, high voltage and whole host of stuff. Have a look at the interim research reports (TJIIRRS), they are especially interesting.
Dave McGuire Runs the lasers mailing list at https://mail.neurotica.com/mailman/listinfo/lasers. It is a great source of discussion for all things laser, vacuum and high-voltage related.
Douglas Little Ruby & Nd:YAG lasers and computer graphics
Milan Karakas Home-built nitrogen and dye lasers
Dalibor Farny He is working on starting to make his own gas-discharge vacuum tubes - glass lathes, vacuum systems, leak testing, etching etc.
Ron Soyland Fantastic site with information on everything vacuum-tube related. Tools, techniques, materials etc. Also see his YouTube channel at https://www.youtube.com/user/glasslinger - many videos on tube making.
Claude Paillard French site with videos of making a triode valve from start to finish - lots of interesting tools.
Aleksander Zawada Hand-made vacuum tubes and glow discharge tubes in Poland
Stephen Hobley Home-built CO2 laser cutter
The Internet Craftsmanship Museum The title says it all - wonderful collection of different craftsmen from many different areas. Run by Joe Martin, president of Sherline Products in California, manufacturer of precision small machine tools.
RTF Technologies Work done by Andrew Seltzman - several electrostatic fusion reactors, refurbishing turbomolecular pumps, 5-axis CNC mill. Lots of photos.
Tatjana Van Vark Her work defies belief - see, in particular, the enigma machine, Antikythera mechanism and harmonic analyser.
http://danyk.cz/ Fantastic collection of high voltage, X-ray, Tesla coil, switchmode power supply, microwave oven stuff