We sure do have a ton of papercraft stuff out there. One of you needs to do all of them and send an image of the entire collection!
If you need a party wagon, check out the template for it here!
And speaking of template, someone has put togeather a huge "construct your own" pony project. Since all of these ponies are the same model, this lets you build yours based on who is your favorite, starting with the base, and following the various packs listed below to finish it off. This one isn't a walk in the part by any means. If you are looking for a challenge, you will probably find one here.
Pinkie Pie Pack
(The rest are coming soon)