Things I hate thinking about

Having two children, i spend a lot of time watching cartoons.  In the interest of full disclosure, I watched a lot of cartoons before the kids (Digimon got me through grad school).  Here's something that's been bugging me:

If instead of us, the earth was populated by intelligent pigs (like at the same level of of sophistication that we are at the moment), what ype of religion(s) would they create?  Obviously they wouldn't be Jewish or islamic, but what and how would they worship?