BBC - KS2 ReviseWise
Site packed with activities and questions to help you prepare for the National Tests. Covers maths, English and science. Contains a guided tour of the website and provides a score sheet.
http://www.bbc.co.uk/schools/revisewise/

BBC Schools - Landmarks Ancient Greece
Covers Key Stage 2 curriculum content for history. Combines images and text to present material designed for both classroom and home use. Links are available to audio material and text versions of pages. Teaching notes and activities are also available.
http://www.bbc.co.uk/schools/landmarks/ancientgreece/main_menu.shtml

Cadbury Learning Zone
Educational resources for teachers and parents from Cadbury's. Includes both online and downloadable activities.
http://www.cadburylearningzone.co.uk

Gridclub
Educational resources and online activities for Key Stage 2 children.
http://www.gridclub.com

Help Your Child
Subscription based service offering e-mailed homework for Key Stage 2 children. Also includes a database of home tutors.
http://www.helpyourchild.co.uk