D.K.
I just bought a Nikon Coolpix S630 and love it. I have an 18 month old who like your son doesn't like to sit still for long. It has the continuous pic option that takes 18 pics at once. This way you can delete the bad ones and keep the good ones. The shot speed is great. An SLR camera has a better speed, but you are also carrying around a bigger camera and a higher price tag. I looked around for months before I purchased this one.
If you buy it at a retail store, it will cost around $275 without tax. I bought it at Amazon.com for $224. They are always offering free shipping or you can look online for a free shipping code.