Drip irrigation systems use less water than watering container plants by hand. Watering plants with the hose or with a watering can, applies a lot of water in a short period of time, and -- especially if the soil has dried out -- most of that water is lost through the drainage holes. Drip irrigation administers the same amount of water -- or less -- over a longer period of time, so the soil is slowly saturated and the soil and roots retain most, if not all, of the water.
Drip irrigation kits are widely available in garden and home supply stores. Few tools are required to assemble a system -- you'll need scissors and something to puncture the tubing. For container plants, you'll need 1/2-inch drip tubing supply line, as well as 1/4-inch solid tubing that extends from the main line to each plant. Goof caps are applied to the end of each section of 1/4-inch tubing. You might consider using an adjustable stream bubbler for individual plants, which is sort of like a miniature sprinkler in each pot.
One of the main advantages of drip irrigation is the time you'll save with automated watering. Watering a large garden and several potted plants can take a huge chunk out of your day, and that doesn't include maintenance work, like weeding. Drip irrigation can be connected to a timer that turns on when you want it to, waters for a designated period of time, and shuts off on its own. This is an especially helpful feature if the garden needs watering while you're away on vacation.
Thomas A. Johnson of "Fine Gardening" magazine raises some good points. In his 2011 article "Water Wisely with Drip Irrigation," he notes that you'll also need a pressure reducer for your outdoor faucet because the water pressure a drip system can handle is far lower than the house system. For another, you'll have to calculate the total gallons per hour used for all the emitters on the drip circuit and make sure that the total doesn't exceed the amount that each system can handle. Those numbers are identified with the kit.