My own belief is that there will always be an outlay; either in terms of your time or the tools you will invest in to develop the knowledge to make money online. If anyone tells you they can make you rich without any investment then I would ask for proof...
On the other hand, if what you are looking for is a way to make a little money while writing online as a hobby then I would agree with Wealthseeker... HubPages and a few other places online will provide revenue share options for your content and despite what most people find when searching the internet, there are a few ligitimate online surveys that will pay a small amount in return for your time..
Overall, it comes down to where you set the bar; high or low..
Do you want to earn a lot of money online to give up your day job, change your future or a little while passing the time away?