Today you can buy half price Denver Zoo tickets courtesy of Living Social. The tickets are $4 for children and $8 for adults and are valid any day excluding special event days like Halloween.
If you are new to Living Social it is similar to Groupon and you can sign up here.
Or if you prefer the zoo for FREE the 2011 Free Days remaining are:
Wednesday, October 12 and Thursday, October 20
Sunday, November 6 and Saturday, November 12
The free days are a blast- we can never go enough but there is a LOT to be said for being able to park right outside the entrance when you are managing all the gear and little people.