During various stages of our girls baby years we have used cloth nappies.
Part if my thinking for going cloth was that we saved money in not buying lots of disposable nappies (i used both, not totally hard core!), good for the environment and one day I could sell them and make it an even cheaper proposition.
Then I discovered you couldn't sell them on ebay so I thought I would just be donating them, but even that proved difficult as most of my friends are getting past the baby years now.
Then I found Gumtree and usednappies.com.au.
I have $110 extra in my pocket this week from selling various nappies!! Very happy.