Hi S C,
This doesn't really have anything specifically to do with Spiderman but this is a great thing to do at birthday parties. We have made "search and find" bottles. You could use "spiderman" themed stuff inside.
*Water bottles
*Bird seed or sand
*Any little trinket that you can fit through the top of a waterbottle
*Glue for the lid for when you are finished
*Laminated card with everything in the bottle written on it. You could even put on there "Thanks for coming to my party! Your child's name.) Punch a hole through it and use a ribbon to tie it onto the neck of the bottle.
Have the kids put one of each of your trinkets (birthday candle, dime, plastic spider, toothpick, safety pin, marble, nail/screw, ect) inside the bottle. Fill half way with birdseed/sand. Glue lid on.
The fun (especially in the car) is trying to find all the things inside the bottle by shaking it.
C.