The EcoTarium in Worcester offers a "2-for-1" military discount. For every ticket you buy, you get one free - same or lesser value.
Adults are normally $14 and kids are $8. So instead of paying $44 for your visit, you should only have to drop $22 (1 adult, 1 kid).
I've honestly haven't been here yet - but I have been saying I want to go for years now. Someday. Someday.