Well I was out looking around today and found a pretty neat product. It is called iBert Safe-t-Seat.
This seat is different from what I have seen before, since your child sits behind the handle bars, normally. What a concept? Will it fit your child?It is designed for children age 4 and under. The minimum age is 12 months as the child needs to be able to sit up well and hold the weight of a helmet on his/her head. The maximum height of the child that can use the safe-T-seat is 42 inches. Kids much taller than that will be uncomfortable. The recommended max weight is 38 lbs. Above 38 lbs and the maneuverability of the bike may be affected.
The cost is around $95 with $15 plus for shipping.