@Linkat,
One thing we did that was a huge hit was a gem hunt, like from Webkinz online. We made it with:
- Plastic easter eggs
- Plaster (if you have the right kind of paint you don't need this step)
- Paint
- Foam board
- Plastic "jewels" -- easy to find at Michael's or someplace like that.
Take apart easter eggs. We covered the outside of each half with strips of plaster first to make them look rougher and "rockier" -- that's not necessary.
Paint the foam board and the outside of the easter egg halves with mottled gray until they look "rocky." (We cut the foam board into an organic shape, kinda kidney-bean-ish, also not necessary.)
Put the easter egg halves on the foam board, round side up.
Put "gems" under about 1/3 of the easter eggs. If you want, you can make a sign with fancy names and post their worth. Put in more of the lower-value ones and only one or two of the high-value ones.
Make about one gem per kid. They get to keep trying (put the board on a small table and go around) until they get a gem. Once they get a gem, they're out/ just watch.
Another easy one (and also with plastic easter eggs) was a "Magical Charm Forest" hunt. I made "pixie pods" by decorating more plastic easter eggs (with glitter glue, just squiggles, no paint). (You could also just get pearly/ iridescent plastic easter eggs and save a step.) Then I put some prizes in them (Webkinz charms, candy, bookmarks, etc.).
Then hide them all over the place, like an easter egg hunt.
I imposed a limit -- like, two eggs each -- because some of the bigger kids would run around like maniacs and grab everything.