The BSA provide a Cub Scout resource of (suggested?) monthly themes. Not only that but they suggest activities to go with it.

Whilst you could easily take the monthly themes and fit them into a UK programme, you could also modify much of it to fit into the programme you already have. With suggestions all the way to 2011, it’s well worth a look.

Cub Scout Monthly Themes

The World Organization of the Scout Movement site has quite a few PDF files for download featuring educational activities for the Cub Scout age group. They come from a book originally published by the World Scout Bureau, Interamerican Region, for Cub Scout leaders and educators. There are over 60 ideas, split into six ‘growth’ areas (similar to our Programme Zones).

Activities for the Cub Scout Section (at Scout.org)