1)Facebook Affiliate Marketing
Create a Page on Facebook about on any topic you are fascinated about. It can be on Tattos, Books, Music etc. Then try to gain some quick fans. In the beginning suggest your friends to join the Page which you've created. Do some article marketing and provide useful tips related to your focused topic on which you've created the page.Paste your page link below the article and tell your readers to visit the link for additional details about the product.
As soon you have a minimum of 1K or one thousand fans, you can pick a product from ClickBank.com, CommissionJunction.com relevant to your niche or topic to promote. But do not over promote. Put it once or twice a month.
It is also based on the same technique used for facebook pages. Just gather more members for your group. Make it interesting and promote your product to make some extra money by affiliate marketing
3)Facebook Application Development:
Did you ever think why people love to sit all day long in front of his computer visiting Facebook? Because of its Games and Applications. If you have some coding skills, then you can take this chance.
We all know about eBay, so there is nothing to give an intro about it. You can easily tell them about your new products you launched on eBay. The interested persons can get notified easily since they're also on Facebook. It is now a good method to buy/sell among your friends. And not only, that it's also a good was to make some extra cash :)