Making Learning Fun has many snowman activities and printables for preschool and kindergarten folks, such as counting, color by number, or simple addition.
snowman math activities, for about K-2nd grade level.
Check for example the estimation activity on that page, or count by fives printable. Another good one is snowman combinations - children figure out how many different kinds of snowmen can be built with a certain number of possible 'parts'.
Then, here's a snowman puzzle from Jigzone. You can solve it right here on my blog with a 20-piece cut, but if you go solve it at Jigzone, you can change the cut so it has more or less pieces.
Jigzone also has another, a snowman photo puzzle.
Snowmen at Night
(The two photos above are real snowmen my kids made, along with some help. Real ones don't always turn out so exactly symmetrical or smooth as what you see in illustrations - but they are FUN to make!)