Just wanted to add an option that I am a big fan of... stove pellets from beetle kill pine trees (we have a lot of those in Colorado). I think that almost falls into the wood chips category but I think the wood pellets are substantially better. I started using them when my chickens were about 2 months old after reading about it on byc and don't have any plans of ever switching to something else.
If you aren't familiar, they don't absorb quite as fast as pine shavings, which is kind of overkill for chicken poop I think, but they do absorb way better than wood chips so it's a good compromise. Other benefits are that they do not get stinky nearly as fast as shavings and last a lot longer, which has made them perfect for a deep litter method in the coop. When they do get wet, they fall apart and sink to the bottom of the bedding as the chickens walk around. I think I mentioned earlier that I am using straw in the run, a very small amount since my hens are laying eggs out there now and needed an outdoor nest, it also fits the bill in that capacity. One straw bale will probably last me well into the winter as little of it as I'm using.
regards,
~Mark