This filter is working up to creating a Rogue-like dungeon hack experience for the surface of the Minecraft world. The idea is that you have encounters periodically while roaming the map. You can extend the encounters by adding your own schematics.
Version 2 of this filter places schematics from a directory onto the surface of the world wherever it finds blocks of a certain type in the selection box.
To use it, unzip into the MCEdit filters directory. Place your custom MCSchematic files that you want placed around the world into this directory. Don't go too big though...
Version 1 of this filter builds an abandoned tower on the surface above Dungeons with spawners below. You can configure the block to be matched for different results.