Run four solenoids, two DC motors, or one bi-polar or uni-polar stepper with up to 600mA per channel using the L293D. These are perhaps better known as "the drivers in our Adafruit Motorshield". If you accidentally damaged the drivers in a shield, you can use one of these puppies to replace it. Or you can breadboard something on your own!

Each chip contains two full H-bridges (four half H-bridges). That means you can drive four solenoids, two DC motors bi-directionally, or one stepper motor. Just make sure they're good for under 600 mA since that's the limit of this chip. They do handle a peak of 1.2A but that's just for a short amount of time. What we like most about this particular driver is that it comes with built-in kick-back diodes internally so you don't have to worry about the inductive kick damaging your project or driver.

There's a PWM input per driver so you can control motor speed. Runs at 5V logic. Good for motor voltages from 4.5V up to 36V! This won't work well for 3V motors. The motor voltage is separate from the logic voltage.