Arduino Home Site
This site is full of great information if you are currently using the Arduino platform or if you’re considering trying it out.
Modern Device offers a ton of great Arduino clones as well as accessories, sensors and components. The pricing is always competitive and the service is great.
Adafruit offers a ton of unique products as well as some of the best how to videos and documentation you’re going to find. Great blog as well.
JCW at JeeLabs offers an Arduino-ish clone with a native radio (RF12B). If you’ve considered building a wireless microcontroller project hurry over there. You can’t beat the value and he offers great customer service as well as technical support on his products. Great blog. Great forum.
Seeed Stuio offers quite a few unique products, low prices an some really nice services. The shipping can be rough on onesy twosy orders but their responsive and eager to earn your business.
This is the go to site if you’re working with Atmel microcontrollers.
I haven’t done any business with Atmel directly but the store they have now is kind of cool. Get your AVR Dragon directly from the source now.
Android meets Arduino
Worth checking out. Arduino meets Android via Buetooth. Bam!