We rented a Bounce House from Bouncing Around for my son's birthday and it was such a hit. The kids did not get out of the bounce house unless it was to eat for about 3 minutes at a time. They were so tired by the end of the day and it was so much fun.
The people from Bouncing Around came into our backyard and set the Bounce House up for us, then after the party they came and took it down. They were very helpful and the cost was very reasonable. I recommend a bounce house for every 4 year old's birthday party!