Here we go. Build your own lawn aerating sandals and take a laps around the yard to open up the thatch, let the air, water and sun in there. Better yet, make a few pairs for your your kids and pay them a quarter to stomp around out in the yard. You'll be treating your lawn, employing your kids, saving money on the rental fees and avoiding those suspicious little earth plugs scattered about the yard.
Here's what you need to get started:
a 2' x 2' square of 1/4" to 1/2" plexiglass
3 yards of velcro tape
a bunch of 1 1/2" galvanized steel screws and nuts
an acrylic drillbit
Remember to keep the jigsaw blade and drill bit cooled down by using cooking spray or dishwashing soap.