Jurassic Fun!  For my son's 6th birthday party, we decided to go with a dinosaur "Jurassic Park" theme.  The invitations were printed on jungle-design paper, and announced "Welcome to a Jurassix Birthday Adventure!", and mentioned some of the exciting activities ("Slide down the giant slide into a pit of "Plesiosaurs!", "Climb into the bounce-house and escape the T-Rex!") and food (Hypsilophodon Hot dogs, Carnotaurus Cake)... The parents said that the invitations alone got the kids excited.  The night before the party, I cut a large T-Rex footprint-shaped hole out of construction paper.  I then took a paint roller and brown washable paint, and rolled dinosaur footprints up our driveway and down our side path, leading up to our wooden gate to the backyard. Large paper block letters on the garage instructed everyone to "FOLLOW THE DINO TRACKS". The wooden gate was decorated with jungle-looking fake plants and vines, and had a large sign that read "JURASSIC PARK" (I used the movie VHS cover to copy the lettering, and using a small paint roller, I then decorated the sign with stencils of dinosaur skeletons). Bamboo torches were lit and stuck in the ground on either side of the gate (and promptly extinguished when the last guest arrived). My son had a large wooden T-Rex skeleton that we'd gotten at Wal-Mart, and we put that by the gate, too. Once inside the gate, guests passed under a banner that read "When Dinosaurs Ruled the Earth", and heard the Jurassic Park movie theme music. Most children went straight to the Jurassic-design bounce house or giant inflatable slide we'd rented. At one point, I ushered the children over to the "Paleo-Paint" Pavilion - a dining canopy set up to look like a dig site - with a long table covered with paints, brushes, cups of water, and 5"-6" plaster-of-paris dinosaur statues that we had made (VERY easy and inexpensive) for them to paint. The children had a BALL painting the dinos all different colors - some of them glow-in-the-dark. The painted statues dried while the children continued to play and eat.  For the cake, I had taken the box-top from a puzzle and had a local bakery scan the scene onto the cake (like they do with photographs). The cake was a HUGE hit. As the children left, they went out to our sandbox where we had a "Dino Dig" sign set up, and they took shovels and dug for dinosaur eggs (plastic eggs from Easter) containing tiny dinosaurs.  Then they were given dino-design goody bags with a few small dino-toys and some dino fruit treats. The children loved being able to take home their works of art and dino-dig finds. Cleanup was a snap, because most of the decorations and signs were simply construction paper that got torn down and thrown away, and the paint on the driveway (and whatever got spilled at the Paleo-Paint) was washed away by a water hose (or rain a few days later!).  The most expensive part of the party was the retned bounce-house and slide.  Other than that, the decorations were either things I had, things I borrowed, or things I made using paper, glue, paint and magic markers. The plaster-of-paris and dinosaur molds can be bought at Wal-Mart, and you just have to start making them a few days in advance so you can make enough of them and they harden in time. A big plus:  I understand that most of the kids fell asleep on the way home in the car!