-Ikea. Not kidding! Our 22 month old LOVES Ikea. There is an entire children's section where they can run, climb on the beds, and play with the toys. Free, and right next to the MOA.
-"Chutes and Ladders," the Hyland Play Area, 10145 Bush Lake Road Three Rivers Park District. GREAT park-huge play area, a ton to do and Free!
-Edinborough Park in Edina. A large indoor play park, great for those cooler days we have had lately.
-Fire Hall Museum. I haven't been here yet, but I read great things about it:
http://www.firehallmuseum.org/
-As suggested, the Como Zoo is excellent! And there is a large park next to it as well for a picnic/running around.
-Also suggested, the Children's Museum in St. Paul is a jewel! There is a ton to do for all ages.
-Thomas the Train is supposed to be coming to Lakeville in August, but tickets still aren't on sale.
-Underwater World at the MOA (in case you missed that)
-Chuck E. Cheese - bad pizza, but kids love it.
-ChooChoo Bob's -
http://www.choochoobobs.com/ We haven't been here yet either, but it looks great!
-Jackson Street Roundhouse -
http://www.mtmuseum.org/jsrh.shtml Another one we haven't hit. Can you tell my little guy likes trains?
-We often times just drive around and run into random parks - there are lots of great ones all over Mpls.
I hope that helps!