USBASP ICSP programmer - You can burn Arduino bootloader or program bare chips (outside of Arduino board).

Hook up wire, 30 AWG, green

Small vibration motor, working voltage 3V

Microcontroller with 8 kB Flash, 12 I/0 pins - it can be programmed using Arduino libraries.

Microcontroller with 4 kB Flash, 6 I/O pins, it can be programmed with Arduino code

Small microcontroller in DIP20

Connect your smartphone with a mircocontroller using audio output.

Micro Metal Gearmotor 100:1

IP monitoring and control - remotely monitor 1 digital input, 1 analog and one 1-Wire. Sends emails and SNMP Traps.

TSH200 - temperature and humidity sensor

Small relay capable switching 8A/250V AC. Coil is powered by 5V - You don't need additional voltage source!

DC barrel power jack 2.1/5.5

DC plug - matches Arduino power connector

Quad 2-input NAND gate

A convenient holder for four AA batteries equipped with a switch

A convenient holder for two AA batteries, equipped with a on/off switch

Inverter for ElWire - input voltage 3V

Using Makerbeam Starter Kit you can build your robot chassis, metal platform for your project and many many other things.

When you want to provide galvanic isolation between two circuits

A small reel of conductive thread for sewing wearable electronics to fabrics. The length of the thread is about 9 meters or 30 feet.

Create wearable electronic device with Arduino LilyPad

Five 1N4007 [1A/1000V] diodes - more useful than you might expect

Convenient and useful power supply with 9V output voltage and maximum output current 1.5A

ATmega328 with bootloader Arduino UNO