Useful Stuff
These are resources that have not found their way onto a unifying page yet.
Everybody asks the question "How wide should my PCB traces be to carry so much current?". This on-line trace-width calculator can help you answer this question.
For serial communications, I recommend TeraTerm (local copy, version 2.3 [950K]) which is a very cool Telnet/terminal client program. It will display more characters than Hyperterm (which won't display characters above 0x7F) and is less of a pain, in general.
For references on LCD programming with the HD44780 LCD controller, you may find useful Fil's HD44780-Based LCD FAQ and How to control a HD44780-Based Character LCD. You can find local mirrored copies of some documents from the latter link here and here. Finally, you can download Application Note 587 from the Microchip web site which shows how to interface a PIC16CXXX to an LCD. A locally mirrored copy of this application note is available here and the associated source code is here.
Here is an alternative PCB material to standard FR-4.
Open Collector is a web site listing free EDA software and circuit designs.
This wire chart has conversions from AWG to wire diameter, resistance, feet per pound of wire, and turns per inch. Nifty!
ePanorama.net has a lot of information for the DIY electronics hobbyist
Mechanical Support
eMachineShop lets you design and manufacture mechanical parts on-line.
BigBlueSaw is the same idea as eMachineShop.
Zero Hour Parts is the same as above, focusing on 5-axis CNC milling, sheet metal components, and welding.
First Cut Prototype is the same idea for plastic parts.
Front Panel Express, LLC has a software tool that allows you to design an aluminium front panel for a project, then submit your design and have it manufactured.
Integrated Ideas & Technologies does laser cut front panels, stencils, and enclosures.
ProtoCase goes beyond front panels and lets you order an entire enclosure on-line.
Pololu does custom plastic laser cutting for $2.50/minute, with no setup fee. No metals, PVC, vinyl, or carbon fiber.
D.C. Water Jet uses abrasive waterjet machining to cut any material.
Padtech Industries can add membrane switches, labels & overlays, shielding, insulators, gaskets, and electroluminescent lighting to your product.
Farwest Fabricators does precision metal fabrication.
AccraFab does sheet metal fabrication.
Tools
Working on electronics projects requires good tools and test equipment. Here are some links I culled from a magazine on some on-line tool vendors. Perhaps someone can flesh these out a bit.
Campbell Hausfeld -- air tools.
Clisby Miniature Machines -- small precision lathes and milling machines.
Elenco Electronics electronic test equipment.
Enco Manufacturing Co. -- shop tools, power tools, hand tools, production tools, plastics, hardware, etc.
FDJ On Time -- miniature jewelry tools, casting equipment, electroplating, mold making, wax working.
Flashcut CNC -- CNC mini mills and lathes.
Grizzly Industrial Inc. -- woodworking and metalworking tools.
Harbor Freight Tools -- hand and power tools, value-priced seller, retail locations in Grand Rapids.
HobbyCNC -- plans and basic starter kits for homemade CNC routers.
Irwin Industrial Tools -- makers of Vise-Grip, web site is mostly informational as their products are available at retail outlets.
Jensen Tools, Inc. -- tools for electronics, hand tools, shop supplies, wide selection.
MAXNC, Inc. -- desktop CNC mills and lathes
MicroKinetics Corporation -- desktop mills and lathes, production machines, stepper motors, servo motors, controls.
Micro-Mark -- precision tools, desktop mills and lathes, ahnd tools, casting supplies, materials.
Minicraft -- precision power tools, hand tools.
Northern Tool & Equipment Co. -- generators, small engines, pressure washers, air tools, mechanical parts, materials, shaft couplers, hydraulics.
Penn State Industries -- hand and motorized tools, mostly for wood.
RB Industries, Inc. -- scroll saws, wood planers, drum sanders.
Rockler Woodworking and Hardware -- hand and power woodworking tools, hardware, wood stock.
S-K Hand Tool Corporation -- hand tools.
Sears, Roebuck & Co. -- don't forget about Sears! They have lots of tools.
Sherline Products -- miniature desktop lathes and vertical mills, both manual and CNC.
Shopsmith, Inc. -- the famous all-in-one woodworking tool: table saw, sander, lathe, horizontal boring machine, drill press.
TAIG Tools -- small desktop mills and lathes.
TestNTools -- computer, electrical, automotive test equipment, some mechanical tools, breadboards, soldering equipment
Toolsforless.com -- power tools and hand tools, hardware, parts, and accessories.
Vermont American Corporation -- saw blades, screwdriver bits, router products, drill bits, abrasives.
Wiha makes a huge variety of hand tools (screwdrivers, hammers, Torx, hex, torque control, sockets, wrenches, etc.)
Woodworker's Warehouse -- woodworking tools, fasteners, hardware, accessories, supplies.
Zona Tool Company -- small precision tools, clamps, pin vices, hack saws.