Materials

Batteries & Solar Cells:
All-Battery | PowerStream | Plastecs | FlexSolarCells | Sundance Solar | Solarbotics

Conductive Hook & Loop:
Less EMF Inc. | hookandloop.com | blockemf.com

Conductive Thread & Fabric:
Bekaert | X-Static | Shieldex Trading | Fine Silver Products | SparkFun Electronics | Less EMF Inc. | Lamé Lifesaver

Electroluminescent Wire, Film & Tape:
EL Wire Cheap | CooLight | Elwire

Electronics:
All Electronics | Digi-Key | Mouser Electronics | Goldmine Electronics | Jameco Electronics | Sparkfun Electronics

Flame Retardant Fabrics:
Dazian Fabrics

Industrial Felt:
Filz Felt | Aetna Felt Corporation | The Felt People | Sutherland Felt Company | Orchard Supply Hardware

LEDs:
HB | Lumex | Super Bright LEDs, Inc.

LED Resistor Calculators:
LEDcalc | Myresistor | HB

Magnets, Mangentic Paint, Magnetic Liquid (ferrofluid):
Container Store | Amazing Magnets | Magnamagic | MUTR

Phosphorescent Materials:
Risk Reactor | MUTR | Mclogan Supply Company | Brightec

Polymorph Plastic (ShapeLock or Friendly Plastic):
MUTR | ShapeLock | The Compleat Sculptor | Sunshine Discount Crafts

Screen-printing Equipment:
Mclogan Supply Company

Shape Memory Alloy (SMA):
Dynalloy, Inc. | Jameco Robot Store | Edmund Scientific

Thermo- & Photochromic Materials:
Textura Trading Company | SolarActive | Color Change Corporation | LDP LLC | CTI Extreme Inks | Union Ink | MUTR | Educational Innovations | Embroider This

Tools:
Jameco Electronics | RadioShack