If you haven't heard of >> Kidsbowlfree.com <<, check it out.
It is a great program that allows children 15 and under to go bowling every day for free.
They can play up to 2 games each day, and I don't think shoe rental is included, but it is an awesome program.
Check the website for participating bowling alleys near you.
(I apologize in advance to my Utah readers as I think there is only 1 alley that does this in Utah).
They also offer an inexpensive membership for the adults in the family so you can bowl with your kids.
Have a great summer and if you have cheap recreation ideas I'd love to hear them.