Yeah, those are the engineering prints from Staples. They are also super huge. I just uploaded a black and white print of each of them onto their website. They are 24x36inches and only cost like $4.00 each.
If you are inviting kids. I like these ideas: -A kid drink for the toast (like cookies and milk) -Activity sheets/placemats/crayons -Legos/playdoh -Hire "babysitter" like a 13 yr old cousin -Kids open candy/snack bar