Our specific model is a Island Hopper Jump-A-Lot Double Slide Bounce House 2012 available from Amazon here. I've been very happy with it, except that the walls along the top slide aren't high enough, and I fear someone running down the slide (as 3-year-olds are wont to do) might fall out. To help prevent this, I sewed on webbing loops and installed a rope safety net, effectively extending the wall upwards.
Step 1: Planning the net
Corvidae hasn't fallen out. However, in the first image, she's standing on the tips of her toes and you can see how close she is to going over. The second and third images are more relaxed postions.
Step 2: Sew on loops
Step 3: Loops while inflated
Step 4: Lace net
The ideal solution would be to sew on more wall material to actually raise the inflated wall. I was concerned I would never actually accomplish this perfect solution before someone fell out, so quickly installed the net. The net might look like it could strangle a child, but the kids aren't totally put out to pasture in the bouncy house -- someone is always paying attention. Untangling a child from the net is something you can walk up and fix while you can't do same after someone falls onto their head.