Work on GPT Sites.
Most people tend to go this route anyways as some of the Get Paid To (GPT) sites tend to have a one dollar minimum payout. All you have to do is complete surveys and offers in which most of them are free. They do have some trial offers that may require a credit card, but they usually don't cost that much. If you do go this route, make sure that you make a lot of email addresses as they are needed in order for you to gain money from different offers. The two top GPT sites; however, are CashCrate and TreasureTrooper.
Write Articles For Site Owners.
Believe it or not, there are tons of sites being created each and everyday. With that in mind, you can join a webmaster forum and connect with some people who are definitely looking for writers for their site. Of course you can try other sites such as Craiglist, but you would get a faster response from a person on a forum than on a classified site.
Create an eBook.
People usually tend to go this route when they are in need to make fast cash online. Reason being is that virtually you can create and sell an eBook if it proves to help someone out with a problem. So if you're an expert about something or just have thorough knowledge about a particular topic, then definitely give this a try.
Sell Items On eBay or Bonanzle.
This is probably the most popular option for people trying to get fast cash. All you really need to do is go around your house and find items that you necessarily don't need or wear anymore. If you are trying to sell clothes, make sure that they are at least in decent condition. If you are selling electronical items, make sure that they work and if they don't work, include it in the listing as some people actually will buy them and use them for parts. Bonanzle is a great site like eBay except for the fact that you don't bid. They are considered to be the best eBay alternative and the trust factor is much more better on that site.
Of course these listed options aren't the only way that you can make fast cash online, but they are the most popular ways. You can even make article writing your full-time job if you wanted to because it's so lucrative. With GPT sites, they may be okay for now, but most people tend to get tired of them quickly. However, there are people who have made it into a full-time job by just getting referrals alone.