I've seen some ramps made from wood, so maybe if you have some extra wood lying around, this could be an idea. Also, if you only have say, one grid, you can bend this into a U shape and use something like fiddlesticks (also bent into a U shape) to balance it on. I have a setup like this if you take a look at my gallery pictures. Then it's kind of like the ramp is used as both a ramp and also a hideout, since the pigs can lay underneath the fiddlesticks.
