Get a copy of the book Toilet Training in Less than A Day by Azrin & Foxx. Don't let the title throw you -- it really works. You can get it from the library or a bookstore or online. Read the book thoroughly and decide if you can follow it exactly. If you can, you'll be done with diapers at 20 months old. I used it for both my daughter and son, and it worked perfectly; they were completely trained on that day and they were wearing underwear -- not pullups or training pants -- without accidents within one week. The program is intense, but one day of hard work sure beats years of changing diapers. Plus your children feel so proud and they are much more compiant at that age, so they are easy to train. However, you must follow it exactly. You cannot allow TV, phone calls, or other people in the house. I have friends who half-heartedly tried it, and of course it didn't work. You give the pretests -- make sure your child obeys you and is physically ready -- and then you must devote one entire day to this process. One thing the book left out was to have them wash their hands after each time they go. Be sure to add that in. Don't buy into the "wait until they're ready -- even age 3 or 4" nonsense. Once they're physically capable (usually 20 months), it's up to you when they're "ready." 20 months is the perfect age, and both you and they will be thrilled.