Today you can even become a freelance writer solely online. I love writing and have been exploring the various opportunities to write online for pay. Based on your current needs and wants, you can pretty much choose how much you make depending on how hard you work. What I mean by that is that you can work part time and work enough to pay your cell phone and electric bills, or you can put it even more work and make a living from your online writing or part time work.
You will not be on a 'cubicle schedule', but your own that works best for you. You write as much as you want that day to achieve your goal and then you proceed with your day. This can be anywhere from 2-6 hrs depending on your work load.
Here are some opportunities to earn money by freelancing online.
Create a blog or blogs. Write great content using Google friendly keywords on topics that interests you and at the same time interests others. Monetize them by adding Google Adsense, affiliate ads, in-text advertising, etc. Promote your blog to bring in traffic. A monetized blog with great traffic, content and keywords can bring you in some money from Adsense and your other advertising. This varies from blog to blog. You could be making mere change and that's it, or you can start out that way at first and then see your income grow.
Another way to make money from a blog is to become a paid blogger or sponsored blogger. You make money by having a blog with good content that is not brand new and signing up for a program like Pay-Per-Post. They will pay you to write ads for products on your blog alongside your regular blog posts. As the name states, they pay you per post. You can also be a paid blogger through someone else's website such as Today.com and Quality Gal [QG pays you for articles also].
Writing for residual income is a great way to make good money in the long run. You won't make anything up front, but you will make royalties from page views and ad clicks [depending on which the company uses]. Writing for revenue sharing sites such as eHow, Hubpages and Bukisa allow you to be free in what you choose to write about rather than choosing an assignment from a list or being given one. Suite 101 also shares their revenue on your articles but is a bit stricter in their guidelines in comparison to the sites I named above.
Writing for upfront pay brings in money for your writing NOW, allowing you to make an immediate living from your writing to pay your expenses or simply to make a little bit of pocket money for fun stuff. Some sites that pay you for each article you submit are Helium, Demand Studios, Textbroker, and Associated Content. All of them pay per article varying from $1-$80 each assignment. Out of these, Textbroker pays the least per article and Helium pays the most. Associated Content gives you the option to be paid through revenue sharing or upfront pay. Check them all out for yourself and see which best fits you.