What about a museum membership so he can take the kids whenever he wants?
I just found this info out from a friend...you can join the Sci-Quest Museum in Alabama
http://www.sci-quest.org/home/memberships/?PHPSESSID=1a5f570441c7589a97b5a62580a5ee2c for $75, and get into ALL of these Chicago museums for free!
The Adler Planetarium & Astronomy Museum
1300 South Lake Shore Drive, Chicago 60605
(312) 922-7827
www.adlerplanetarium.org
F: Two adults and up to six children (under 18) living in one household
Burpee Museum of Natural History
737 North Main Street, Rockford 61103-6971
(815) 965-3433
www.burpee.org
F: Two adults (parents/grandparents) and children 17 and under in household
Chicago Children's Museum
700 East Grand Avenue at Navy Pier, Chicago 60611
(312) 527-1000
www.chicagochildrensmuseum.org
F: Up to four people residing in the same household
Children's Discovery Museum (IDs)
101 E. Beaufort, Normal 61761
(309) 433-3444
www.childrensdiscoverymuseum.net
F: Two adults and their children living in the same household. Residency rule enforced.
Discovery Center Museum
711 North Main Street, Rockford 61103
(815) 963-6769
www.discoverycentermuseum.org
F: Two adults and two children living in the same household under the age of 18
The Field Museum of Natural History
1400 South Lake Shore Drive, Chicago 60605
(312) 922-9410
www.fieldmuseum.org
F: Two adults and all children under 18 living in the same household OR two grandparents and their grandchildren under 18
International Museum of Surgical Science
1524 North Lake Shore Drive, Chicago 60610
(312) 642-6502
www.imss.org
F: Two adults and all children 18 and under living in the same household
Lake County Discovery Museum
27277 Forest Preserve Drive, Wauconda 60084
(847) 968-3400
www.lakecountydiscoverymuseum.org
F: Two adults and three children
Lakeview Museum of Arts and Sciences
1125 West Lake Avenue, Peoria 61614-5985
(309) 686-7000
www.lakeview-museum.org
F: Parents and children under 18
Museum of Science and Industry
5700 South Lake Shore Drive, Chicago 60637
(773) 684-9844
www.msichicago.org
F: Two adults and all children under 18 living in their home, and an additional guest (adult or child)
Orpheum Children's Science Museum
346 North Neil Street, Champaign 61820-3614
(217) 352-5895
www.orpheumkids.org
F: Two parents and three children
Peggy Notebaert Nature Museum
2430 North Cannon Drive, Chicago 60614
(773) 755-5100
www.naturemuseum.org
F: Two adults and all children 18 years old and under in the same household. Special exhibitions may require additional fees.
The Science Center of Southern Illinois
1237 East Main Street, C-8, Carbondale 62901
(618) 529-5431
www.yoursciencecenter.org
F: Parents/Guardians and children under 18 in immediate family
SciTech Hands-On Museum
18 West Benton Street, Aurora 60506
(630) 859-3434
www.scitechmuseum.org
F: Up to 6 immediate family members (including grandparents); additional at general admission rates.