We finished porting the AFmotor library to the Arduino Mega, if you have an Arduino Mega & and an Adafruit motor shield they now play together nicely.

What is the Adafruit motorshield for Arduino?

• 2 connections for 5V ‘hobby’ servos connected to the Arduino’s high-resolution dedicated timer – no jitter!
• 4 H-Bridges: L293D chipset provides 0.6A per bridge (1.2A peak) with thermal shutdown protection, internal kickback protection diodes. Can run motors on 4.5VDC to 36VDC.
• Up to 4 bi-directional DC motors with individual 8-bit speed selection (so, about 0.5% resolution)
• Up to 2 stepper motors (unipolar or bipolar) with single coil, double coil or interleaved stepping.
• Pull down resistors keep motors disabled during power-up
• Big terminal block connectors to easily hook up wires (10-22AWG) and power
• Arduino reset button brought up top (Diecimila/Duemilanove only)
• 2-pin terminal block and jumper to connect external power, for seperate logic/motor supplies
• Tested compatible with Diecimila/Duemilanove (NG is next!)
• Download the easy-to-use Arduino software library, check out the examples and you’re ready to go!