If you travel a lot or live near a zoo or science center you might want to consider a science center and/or zoo membership. These are all good for a year & you can usually activate them over the phone or online. You don't have to live near the one you buy, but these are some of the best prices I have found. Typically a family is up to 6 people.
I tried to use my Toledo membership at Great Lakes & they wouldn't let me. They said because I lived less than 90 miles from Cleveland I couldn't use a membership except for Great Lakes for free or McKinley for 1/2 price. They ended up letting me pay half price because they had given me incorrect information when I called. I just say this as a warning about the 90 mile rule. I think this applies at all of them.
Science Center Memberships:
McKinley Museum in Canton - $58 for a family.
Pros - 350+ science centers for free, including COSI & Clev Natural History
Cons - Great Lakes Science Center 1/2 price (Great Lakes General Admission - Adult $17, Kids (2-12) $14), doesn't reciprocate to Pittsburgh Children's Museum
Boonshoft Discovery in Dayton - $115 for a family (up to 6 kids)
Pros - 350+ science centers for free, 150+ zoos - most for half price
Cons - Cincinnati Museum Center, Cincinnati Museum of Natural History 50% off, COSI is 50% off (COSI Classic Exhibits & live shows - Adults $25, Kids (2-12) $20). This wouldn't work at Great Lakes if you live less than 90 miles from Cleveland.
Akron Zoo - $80 for a family
Pros - 150+ zoos - most for half price, Akron Zoo & Parking free (Summer Adult $12, Kids 2-14 $9)
Cons - Cleveland zoo is 1/2 price (Cleveland Zoo (Summer Adults $15, Children 2-11 $11)
Cleveland Zoo - $99 for a family. Buy on line with code A100 & save 15%
Pros - 150+ zoos - most for half price, free parking
Cons - Akron zoo is 1/2 price (& you have to pay $3 to park there)
In February I got a membership to Western North Carolina Nature Center in Asheville. It give free admissions to science centers AND 1/2 price to zoos. It's $69 for a family membership for a year. We have already more than paid for it. I haven't tried to use it locally other than McKinley museum, where I didn't have a problem.
Here's a link to Staycations around the country. It's also a good resource if you are visiting one of these areas.
Bank of America or Merrill Lynch credit and debit cardholders get free admission into 150 zoos, science centers, & children's museums around the country the first full week-end of each month. Check out the list here.