How would you go about setting up explosions, where you can vary the size and other things and have it semi realistically displace the objects around it?
I don't really know, but I'd try something like
1. Loop through all the objects within a bounding sphere 'blast radius' centered at the explosion point.
2. Apply a force on each object that originates at the center of the blast, with an inverse relationship to distance.
3. Optionally apply a small random rotation factor to each object so they don't just separate perfectly in the same positions.
That actually sounds kinda fun..