Another milestone. On November 5, one day before he turned 20 months, we turned Christian forward facing in his carseat. We had wanted to keep him rear facing as long as possible because it is safer. Unfortunately, he has reached the height limit for rear-facing in this carseat so we had to turn him. His reaction was a little perplexed. It was quite funny to see the look on his face the first time he got in the seat and realized something was different. He was quite happy being rear-facing, and doesn't seem to care that he's been turned around either.
The following sites explain why it is best to keep kids rear facing as long as possible. In Sweden, most kids are kept rear-facing up till age 5.
http://www.car-safety.org/rearface.html
http://www.cpsafety.com/articles/StayRearFacing.aspx (has video clips of what happens to front facing and rear facing child in collision)