In addition to the uber-useful AeroGarden below, John's parents also gave me a nice steamer for Christmas. The way it works is very similar to an electric kettle. You fill the base with water before turning it on, and a heating element in the water heats it to boiling temperature.
Next, add your ingredients to the plastic chambers. In my first few tries, I used broccoli as my test food.
Then, set the timer to the desired steaming time. Here, I'm steaming the broccoli for about 15 minutes.
Within minutes, the chambers fill with steam, which cooks the contents of the chambers.
Finally, a few minutes later, you have perfectly steamed foods!
The steamer came from Cooks Essentials. It was very easy to use and clean, although it would have been great if the plastic parts were able to be washed in the dishwasher. Regardless, I've used it to steam large quantities of veggies, and they've all turned out just the way I like them -- colorful and slightly crunchy. If you like yours a bit tender, just adjust the timing on the base.