This is a great museum. I became a member in May, 2011 and have renewed my membership. Living here in the valley in the summer leaves me with a very limited amount of activities that I can take my kids to without breaking the bank. The membership for a family of four is VERY affordable.
The kids (9 year old son and 4 year old daughter) love to visit the museum and have yet to get tired of it. They have activities all throughout the year that you can attend and not feel like it was a waste of time.