Todays Living Social Deal is 50% off two adult tickets, making it just $8 (reg $16). This would make for a really fun date and a perfect time to go if you haven't been there before.
Admission for children under 6 years of age is always FREE! Here is a link to their site if you want to scope the place out first.
You have until November 1st 2011 to use your voucher.