When most people think about earning extra money with a part-time gig, they think department store or restaurant. But there are plenty of less conventional ways to get some extra cash. Here's four to get you started

First? Sell your body to science - starting with bodily fluids.

Selling blood is one option. Selling plasma is another. To be eligible, you must be between 18 and 65, weigh more than 110 pounds and be in good general health. Sound creepy? Well, consider that you're also saving lives while making a buck.

Sign up for a clinical trial. These test safety and effectiveness of new medicines, devices and medical therapies. A 2 or 3 day trial can pay between 1 and 2 grand. The National Institutes of Health runs this searchable database. Just make sure you talk to your doctor first and read all the fine print before you sign up. The money might be good - but the side effects may not be.

Number three? Sell your special talents for five bucks a pop at fiverr.com. Sing a song, teach someone a new language or help someone make a decision. It's free to join and the website doesn't take a commission.

Last idea? Trade in your unused DVDs, games, electronics, and books. Many sites like this will give you credit for your stuff. For a DVD copy of Avatar, Amazon will pay you up to $5.30. A hard cover copy of "A Tale of Two Cities" will bring in 10 bucks. You can also sell stuff on eBay and Craigslist.

Bottom line? Just as there are a ton of ways to spend money, there are a ton of ways to make it too. Want more ideas? They’re at Money Talks News.com.