For my son's 4th birthday party he wanted a train theme. I stamped the invitations which said:  Front:  All Aboard! Inside:We're CONDUTING a party! Engineer:  Michael, Station: The Poepping Depot Arrival (date/time)  To reserve your seat: (phone#)  GAMES: We played Pin the 1 on Thomas. I used an overhead projector to blowup an image of Thomas.  I colored it w/ markers.  I used the Ellison machine to die cut #1 for each kid.  The child that came closest won a prize.  We also played a bean bag toss game.  I made black bean bags to look like coal. I then covered a box w/ blue paper and the #4 (Gordon's Tender/my son's age). The kids threw to "coal" into the "tender".  Winner got a prize. We also played "Pass the Whistle"-same thing as hot potato, just using a train whistle. We found a Thomas CD at totallythomas.com, and used this musice for the game. Lastly, a pinata and a moonwalk. PRIZES: I found a board book that had 4 puzzles inside (each page was a different puzzle.  I picked those up from a Scholastic book order.  These were given out to game winners.  FOOD:  Our cake was awesome (thank you Shaker Baker!!)  It was a 3-d square made to look like a train table set.  The baker had placed 3 cup cakes upside down to create mountains.  The cake was bordered by tracks.  The tracks created the #4 at a "switch"!  Was also found train shaped macaroni. We paired that w/ regular mac & cheese and had "trains and tracks". The rest of the food was normal-fruit salad, pasta salad, ham/turkey sandwiches, chips... LOOT BAGS:  each child received an engineer's hat, a wooden whistle, train tattoos, a train related book (purchased many different titles to avoid siblings receiving the same book, train shaped suckers that we purchased while riding the Heber Creeper (Heber, Utah), and passes for the train ride at the Zoo. Bags were plain brown gift bags stamped w/ names and a train. THANK YOU:  I stamped the thank you cards. They read:CHOO-CHOO  THANK YOU on front, and the message was handwritten inside.