My son is so into dinosaurs right now, so it was no question as to what kind of party we would have for his 5th birthday.    FOOD: We had it mid afternoon, so we only served light snacks - Prehistoric puffs (Pirates Booty), Stegosaurus Jello Jigglers (we used strawberry, so I just put the excess on a plate and let my guests' imagination run wild - they thought it was volcanic lava!), and a veggie platter (fixed in the shape of a skeleton)  When the guests entered, they were given a pair of small boxes with the hole cut out for dinosaur feet (on Family Fun website). I had cut out shapes out of craft foam (including white claws).  They were able to glue them on to create their own.  There was also downloaded dinosaur coloring pages if they preferred and they could use the crayons on the dinosaur feet.  When they were done with their craft, we had the kids put on their feet and had a parade (Dinosaur Parade music - the last song on Wee Sing Dinosaurs - Not Wee Sing and Learn Dinosaurs).  My husband camped it up and they LOVED it.    From there, we had covered diaper cartons with Brown Paper bags and hid cardboard T-Rex skeleton bones and some plastic dinosaurs in packing peanuts. We tried to be methodical, but with 16 5 year olds, it's not always possible. Eventually, they ripped into them liked rabid dogs!  IMPORTANT NOTE: put the boxes on top of a large tarp or blanket for easier clean up! After discovering all the pieces, they put it together.  From there, we searched for fossil stones - recipe from kidsconcoctions.com or you can get the book by Danita and John Thomas.  I put them in semi-plain view and they took them back to the craft tables and cracked them open to find dollar store dinosaurs! Then we had stegosaurus cake.  The body was from a Barbie dress form, the head was a muffin, the legs and tail - twinkies propped up with Marshmallows with pistachio shells as claws and of course, frosted green and candy corn spikes. Sounds kind of gross, but everyone was wowed with the creativity and the kids didn't seem to complain.  After cake, we took the kids outside (rare beautiful day in November in SF) and played with a homemade pinata. We used a balloon as a base and my husband used cardboard for the tail and head/neck and legs. It was great for the 5 year old set because the commercial pinatas these days are made out of indestructible cardboard and all I used was paper mache! It broke, but everyone got a turn to hit it. Then we sent them off with all their goodies and a CD of dinosaur songs I had burned - I kept a look out for good deals and found 50 cdr's and sleeves for $10. Can't beat the 20 cent favor (all songs downloaded off of free sites)! Every year I say how much of a pain it is to do it myself, it's so much easier to go to Chuck E. Cheese or bowling, etc.  but my parties are the most creative one they go to all year and my kids will remember it for years to come!