For my sons 5th birthday I chose a Pirate theme. He had shown a lot of interest in treasure maps, so I thought this would be perfect. I printed invitations out on my computer on parchment paper with the usual pirate lingo: "Ahoy, Matey, Capt'n Kyle is Havin' a Bloomin' Pirate Party. Chart yer course fer...(address), He needs shipmates to swab the deck, walk the plank and hunt for long lost treasure. Wave yer flag if ye be attending. See ya thar! Aarrgghh! If ye Dare!" I burned the edges of the invitations and rolled them up and inserted them into a plastic soda bottle (all labels removed). I addressed each bottle and sent them through the mail for $.55 each. This was a big hit.  We decorated the yard using a large blue tarp to create the "ocean" ( my husband is very handy he built a wood frame about 18 inches high and lined it with industrial plastic then the blue tarp) so it was actually a very large wading pool. We filled the ocean with rubber fish, seahorses, plastic oyster shells, lobsters and crabs.  We had a boat floating in the ocean with a mermaid on the front. There was fishing net in one corner to catch the lobster. On one corner of the "ocean" we had three tree stumps tied with rope to look like a pier, with a wooden anchor. On another end of the "ocean" was the beach. We poured sand on the outside of the wading pool and filled it with seashells, starfish and sand toys. We hung a large pirate flag from a pole. I had a loot bag ready for each child when they arrived that was filled with a pirate hat, pirate sword, eye patch, and telescope. I made the loot bags with left over fabric I had, each was a different color so the kids wouldn't get them mixed up. I found all the pirate supplies in Oriental Trading. We had pirate tattoos and black face paint for the kids to wear.  Some of the food served were Sea Faring Packets (tin foil packets filled with shrimp, clams and scallops and corn on the cob) cooked on the grill. A large fruit plate (to prevent scurvy). And a lot of the regulars that most kids will eat.  For the big finale, we made a treasure map out of a brown grocery bag and burned the edges. The map included landmarks in the yard for the kids to follow. We are lucky to have a very large backyard so the kids had a good long hunt. At the end of the hunt was a wooden treasure chest (actually a toy box in the shape of a treasure chest). It was filled with chocolate gold coins, Mardi Gras beads, and tons of toys for the kids to fill up their loot bags. I got this idea a good 2-3 months before the party and right away started collecting small toys and such to fill the treasure chest. So I didn't have the large expense of filling the chest up all at once.