Garden centres sell glass globes designed to water your plants for you, but a better solution may be this attractive wine-bottle-to-plant-waterer DIY project. The wine bottle holds more water than the typical globes, plus you get to drink wine to empty the bottle.
Wallace Gardens' project on Hometalk is a more sophisticated version than the wine bottle and Coke bottle projects we've seen before (which have you just sticking the bottle in the dirt or using a plastic stem): The project involves using copper tubing to create a durable stem that helps balance the weight of the glass bottle.
If you don't care to mess with the copper tubing, Curbly points out you can just use four terracotta stakes, like these ones from Uncommon Goods.
Either way, your plants will be happy to have a steady supply of water. (Do thoroughly rinse the wine bottles out first.)