kid's to-do places

I have found the most wonderful park in London called Coram's field.  It has a mini petting zoo with goats, sheep, rabbits, parakeets, geese, etc... and a tennis court size sandbox with running water . 
This place also has indoor play rooms full of toys for under 5 year olds, including painting and musical instruments, AND there's a music class for under 4's every Wed.  for free!!

Some one recently told me about a science museum for children, but I forgot the specifics.

Does anyone know info on the science museum, and/or other inexpensive/free places for the kiddies?

Thanks   

The Science Museum is in South Kensington (District, Circle or Picadilly lines).  One only need follow the signs once off the Tube.  The Natural History Museum is next door as well.  A nice place for some ideas is http://www.kidslovelondon.com

thanks Elle, what a fun website! 

hey, Friday through Monday (July 23-26) 10am-6pm, there is a free event with puppets, dancing, music, painting, storytelling, waterplay and more at Somerset House.