I've been thinking about doing the same thing as my dd is about to turn 4.
I know someone that had three jars, one for short term savings, one for long term savings, one for tithes.
I've also heard of starting the week with an amount in a jar with quarters and when a child misbehaves you take a quarter out into the empty jar, it can be earned back as well. (not sure if this works, only heard about it).
My thoughts on parenting are that we are preparing them for adulthood. So, since we work, and get paid as adults, I plan to begin giving her some chores and then giving her money for it when she finishes them. I am hoping to teach her that if she works hard she will be rewarded.
I'm going to check back tho for some great advice on this one too! thanks for posting, good question!