Over the past few years we have really enjoyed keeping chickens, at first we kept onlying laying hens for eggs. At one time we bought 5 week old silke chicks and raised them, it turned out that three of the five were roosters, and as we had no plans on eating them, we sold them.
Last year we kept hens and roosters, with one pair hatching out nine cute chicks. Sadly a fox killed the other hen so that rooster was left alone.
Keeping chickens as pets has been rather fun, and except for when we had the roosters with the hens we have enjoyed their eggs too. I totally encourage others to keep chickens as backyard pets and wish more cities allowed people to do so - I am lucky to live in the country so there are no regulations in this regard.
I have encountered many interesting questions about keeping and raising chickens had have provided some links here in case anyone is wondering the same thing.
Why Won't My Chicken Eggs Hatch? - This article addresses common reasons why eggs do not hatch.
How are Chicken Eggs Formed? - Interesting, weird and maybe not good to read before breakfast.
Abnormalities in Chicken Eggs - The eggs you get at stores are often perfect but not all eggs are so perfect.
When will my Hens Start Laying? - Usually hens start laying eggs at five months of age, but not always.
Below are some articles specifically related to chicken breeds. Selecting the right breed is very important, some chickens are friendly and make great pets, others are suited for laying, meat, or are dual purpose.
About Orpington Chickens - A popular dual purpose chicken breed
Araucana and Ameraucan Chickens - The ones that lay blue or green eggs.
Bantam Chickens - Small chickens well suited to being kept as pets.
Silkie Chickens - Fluffy and cute ones common as pets.
Of course there are more breeds than those listed, but these are the ones I am most familiar with and have articles on at this point. You might also want to read an article on General Chicken Trivia.
Overall I have found keeping chickens to be great, they are not as stupid as people often make them out to be, and they enjoy being out free range in the yard. Chickens will eat slugs, grasshoppers, and other insect pests too - even ticks. They do need to be confined in a coop at night for their own safety. Sometimes they may want to roost in a tree but they may be vulnerable from predators (mink, raccoons, and so forth).